KR102617584B1 - Prepregs, cores and composite articles including expandable graphite materials - Google Patents

Abstract

Prepregs, composites and articles comprising an expandable graphite material dispersed in a thermoplastic layer are described. In some cases, the thermoplastic composite includes a porous core layer comprising a plurality of reinforcing fibers and a thermoplastic material, the porous core layer further comprising expandable graphite particles uniformly dispersed in the porous core layer.

Description

PREPREGS, CORES AND COMPOSITE ARTICLES INCLUDING EXPANDABLE GRAPHITE MATERIALS}

priority application

This application relates to and claims the priority and benefit of: U.S. Provisional Application No. 62/079,288, filed November 13, 2014, the entire disclosure of which is hereby incorporated by reference for all purposes. .

technology field

The present application relates to composite articles comprising one or more expandable graphitic materials. In a particular form, a composite article comprising a thermoplastic core comprising a thermoplastic material, a plurality of reinforcing fibers, and an expandable graphite material disposed or dispersed in the core is described.

Articles for automotive and building materials applications are typically designed to meet numerous competitive and stringent performance specifications.

summary

Certain types of prepregs, cores and composites described herein provide desirable properties including, but not limited to, more uniform loft across the surface of the article, better acoustic properties, flame retardancy, improved processability and improved usability.

In a first aspect, a thermoplastic composite comprising a porous core layer comprising a plurality of reinforcing fibers and a thermoplastic material, dispersed in the core layer, for example, an expanded graphite (EG) material uniformly dispersed in the pores of the porous core layer. A porous core layer further comprising EG particles is provided.

In certain forms, expandable graphite materials such as particles are effective for increasing: the thickness of the porous core layer by at least 50% after heating with radiation at or above the loft onset temperature of expandable graphite materials (e.g.: EG particles) ) and/or and resin melting point. In another form, the expandable graphitic material, such as EG particles, is selected to be substantially insensitive to loft upon convective heating. In some cases, the plurality of reinforcing fibers includes at least one of glass fibers, aramid fibers, graphite fibers, carbon fibers, inorganic mineral fibers, metal fibers, metallized synthetic fibers, and metallized inorganic fibers. In other cases, the thermoplastic material is at least one of polyethylene, polypropylene, polystyrene, polyimide, polyetherimide, acrylonitrile styrene, butadiene, polyethylene terephthalate, polybutylene terephthalate, polybutylene tetrachlorate, polyvinyl Chloride, polyphenylene ether, polycarbonate, polyestercarbonate, polyester, acrylonitrile-butylacrylate-styrene polymer, amorphous nylon, polyarylene ether ketone, polyphenylene sulfide, polyaryl sulfone, polyether sulfone, Includes poly(1,4 phenylene) compounds, silicones, and mixtures thereof. In some embodiments, the thermoplastic material includes particles and the average particle size of the particles of the thermoplastic material is about the same as the average particle size of the expandable graphite particles. In certain examples, the porous core layer provides flame retardancy and is halogen-free. In some embodiments, the flame retardant can be present in the porous core layer, where the flame retardant includes at least one of N, P, As, Sb, Bi, S, Se, or Te. In other cases, the porous core layer provides flame retardancy and does not include a flame retardant. In some embodiments, the porous core layer may include another lofting agent that is also effective in allowing the lofting agent, such as an expandable graphite material, to function as a lofting agent in the porous core layer.

In another aspect, a thermoplastic composite is disclosed, wherein the porous core layer includes a web of an open-celled structure comprising random alternations of reinforcing fibers held together by a thermoplastic material, further comprising the porous core layer: an expanded graphite material; , for example, EG particles (homogeneously dispersed in a web with an open cell structure).

In certain embodiments, the expandable graphitic material, such as EG particles, is effective to increase the thickness of the porous core layer, and/or and the resin melting point, by at least 50% after radiation heating above the loft onset temperature of the expandable graphitic material, e.g., particles. do. In other embodiments, the expandable graphite material, such as particles, is selected to be substantially insensitive to loft upon convective heating. In further instances, the plurality of reinforcing fibers includes at least one of glass fibers, aramid fibers, graphite fibers, carbon fibers, inorganic mineral fibers, metal fibers, metallized synthetic fibers, and metallized inorganic fibers. In another embodiment, the thermoplastic material is at least one of polyethylene, polypropylene, polystyrene, polyimide, polyetherimide, acrylonitrile styrene, butadiene, polyethylene terephthalate, polybutylene terephthalate, polybutylenetetrachlorate, poly Vinyl chloride, polyphenylene ether, polycarbonate, polyestercarbonate, polyester, acrylonitrile-butylacrylate-styrene polymer, amorphous nylon, polyarylene ether ketone, polyphenylene sulfide, polyaryl sulfone, polyether sulfone. , poly(1,4 phenylene) compounds, silicones, and mixtures thereof. In some examples, the thermoplastic material includes particles and the average particle size of the particles of the thermoplastic material is about the same as the average particle size of the expandable graphite particles. In other cases, the average particle size of the expanded graphite is at least 50% of the average particle size of the thermoplastic material. In a further example, the porous core layer provides flame retardancy and is halogen-free. In some embodiments, the flame retardant is provided in the porous core layer, where the flame retardant includes at least one of N, P, As, Sb, Bi, S, Se, or Te. In other cases, the porous core layer provides flame retardancy and does not include a flame retardant. In certain instances, the article may include another lofting agent in the porous core layer that is also effective in allowing the expandable graphite material to function as a lofting agent.

In a further aspect, a porous core layer comprising a plurality of reinforcing fibers and a thermoplastic material, further comprising a thermoplastic composite sheet wherein the porous core layer comprises: an expanded graphite material, e.g.: EG particles (core layer, e.g. For example, uniformly distributed in the pores of the porous core layer, and a shell disposed on at least one surface of the porous core layer).

In certain embodiments, the sheet includes an additional porous core layer disposed between the porous core layer and the skin. In another embodiment, the additional porous core layer includes a thermoplastic material, a plurality of reinforcing fibers, and an expandable graphitic material such as EG particles. In a further example, the expandable graphitic material such as EG particles of the additional porous core layer are uniformly dispersed in the additional porous core layer. In some embodiments, an additional porous core layer with expanded graphite material (e.g., EG particles) is gradiently distributed in the additional porous core layer. In certain configurations, the porous core layer provides flame retardancy and is halogen-free. In some embodiments, the porous core layer provides flame retardancy and does not include a flame retardant. In certain embodiments, the expandable graphite material (e.g., EG particles) is effective to increase the thickness of the porous core layer by at least 50% after radiation heating above the loft onset temperature of the expandable graphite particles. In some examples, the sheet includes another lofting agent that is also effective in functioning as a lofting agent, such as an expanded graphite material, in the porous core layer.

In another aspect, a thermoplastic composite sheet comprising a porous core layer comprising a web of an open-celled structure comprising random crossings of reinforcing fibers held together by a thermoplastic material, further comprising the porous core layer comprising: an expanded graphite material (e.g. For example, EG particles) (uniformly dispersed in a web of an open cell structure; and a shell disposed on at least one surface of a porous core layer).

In certain cases, the sheet further includes an additional porous core layer disposed between the porous core layer and the skin. In some embodiments, the additional porous core layer includes a thermoplastic material, a plurality of reinforcing fibers, and an expandable graphitic material such as EG particles. In another example, an additional porous core layer with an expandable graphitic material (e.g., EG particles) is uniformly dispersed in the additional porous core layer. In some embodiments, the expandable graphitic material such as EG particles of the additional porous core layer are gradiently distributed in the additional porous core layer. In some forms, the porous core layer provides flame retardancy and is halogen-free. In another form, the porous core layer provides flame retardancy and does not contain a flame retardant. In some embodiments, the expandable graphite material such as EG particles is effective to increase the thickness of the porous core layer by at least 50% after radiation heating above the loft onset temperature of the expandable graphite particles. In other cases, the sheet comprises another lofting agent that is also effective in functioning as a lofting agent, such as an expanded graphite material, in the porous core layer. In some embodiments, the shell can include expandable graphite particles.

In a further aspect, a porous core layer comprising a web of an open-celled structure comprising random crossings of reinforcing fibers held together by a thermoplastic material, further comprising a non-covalently bonded expandable graphite material, e.g. A thermoplastic composite sheet comprising a porous core layer comprising non-covalently bound expandable graphite particles uniformly dispersed in a web and a skin disposed on at least one surface of the porous core layer is described.

In certain embodiments, the sheet may include covalently bonded expandable graphitic material such as EG particles dispersed in a web. In some forms, the non-covalently bound expandable graphitic material, such as EG particles, and the covalently bound expandable graphitic material, such as EG particles, are present in about equal amounts. In other cases, covalently bonded graphitic material such as EG particles are present in a gradient distribution in the web. In some embodiments, the non-covalently bound expandable graphitic material such as EG particles is present in a flame retardant amount. In certain examples, the porous core layer provides flame retardancy and is halogen-free. In further embodiments, the sheet may include a flame retardant in the porous core layer, wherein the flame retardant includes at least one of N, P, As, Sb, Bi, S, Se, or Te. In other embodiments, expandable graphitic materials, such as EG particles, are effective in increasing the thickness of the porous core layer by at least 50% after radiation heating above the loft onset temperature of: EG particles. In other cases, the sheet comprises another lofting agent that is also effective in functioning as a lofting agent, such as an expandable graphite material, in the porous core layer. In some embodiments, the shell may comprise covalently bonded expandable graphitic material such as EG particles or non-covalently bonded expandable graphitic material such as EG particles.

In another aspect, a method comprising the following steps: a combination of the following: thermoplastic material, reinforcing fibers and expandable graphitic material, such as EG particles (in a mixture forming an agitated aqueous foam), on a wire support. Dispensing the agitated aqueous foam, discharging water to form the web, and heating the web to a first temperature above the melting temperature of the thermoplastic material, wherein the first temperature is below the loft onset temperature of: expandable graphite Materials (e.g., EG particles) that produce substantially no loft are provided. If desired, pressure may be applied to the web to provide a thermoplastic composite sheet comprising an expandable graphite material such as EG particles uniformly dispersed in the provided web.

In certain cases, the venting step removes less than 5% of expanded graphite material, e.g., EG particles, in a stirred aqueous form disposed on a wire support. In other embodiments, the method may be used to remove expanded graphite. and mixing the agitated aqueous foam until the material such as EG particles is uniformly dispersed in the agitated aqueous foam. In some embodiments, the method includes heating the web using convection heating. In certain embodiments, the method includes applying pressure to a thermoplastic composite sheet. In some examples, the method includes heating the thermoplastic composite sheet using radiation heating. In another form, the method includes the following steps of placing: additional expandable graphite material, such as EG particles, on the surface of the thermoplastic composite sheet. In some embodiments, the method includes adding a lofting agent to the agitated aqueous foam. In a further example, the method includes coupling a thermoplastic composite sheet to a skin. In some examples, the method includes coupling the thermoplastic composite sheet to an additional thermoplastic composite sheet comprising thermoplastic material, reinforcing fibers, and expandable graphite material such as EG particles. In some embodiments, the method includes selecting a thermoplastic material to comprise the particles and selecting an average particle size for the expandable graphite particles to be about the same as the average particle size of the particles of the thermoplastic material.

In a further aspect, a method comprising the following steps: a combination step of: thermoplastic material, reinforcing fibers and expandable graphite material, such as EG particles, in a mixture, mixing the mixture to provide a substantially uniform dispersion of Steps: in a mixture of expandable graphitic material, such as EG particles, placing the mixture on a wire support, draining water from the placed mixture to form a web, and optionally a substantial rope of expandable graphitic material, such as EG particles. A step of heating the web under first heating conditions is provided to melt the thermoplastic material without melting. In certain forms, pressure may be applied to the web to provide a thermoplastic composite sheet comprising expandable graphite particles dispersed in the web.

In certain examples, the draining step removes less than 5% of the expanded graphitic material, such as EG particles, from the mixture disposed on the wire support. In other examples, pressure is applied without causing covalent bonding in the web to an expandable graphitic material, such as EG particles, thermoplastic materials or reinforcing fibers. In other cases, the method involves heating the web using convection heating. Includes steps. In certain examples, the method includes applying pressure to a heated thermoplastic composite sheet. In a further example, the method includes heating a thermoplastic composite sheet using radiation heating. In another form, the method includes placing additional expandable graphitic material such as EG particles on the surface of the thermoplastic composite sheet. In some embodiments, the method includes adding a lofting agent to the mixture. In some embodiments, the method includes coupling a thermoplastic composite sheet to a skin. In certain examples, the method includes coupling the thermoplastic composite sheet to an additional thermoplastic composite sheet comprising thermoplastic material, reinforcing fibers, and expandable graphite material such as EG particles. In some embodiments, the method comprises selecting a thermoplastic material to comprise the particles and selecting an average particle size for the expandable graphite particles to be about the same as the average particle size of the particles of the thermoplastic material or the average particle size of the particles of the thermoplastic material. and selecting the average particle size of the expandable graphite particles to be greater than about 50% of the .

In another aspect, a thermoplastic composite is provided, comprising a porous core layer comprising a plurality of reinforcing fibers and a thermoplastic material, and further comprising an expandable graphite material such as EG particles dispersed in the pores of the porous core layer. In certain cases, the expandable graphitic material, such as EG particles, is a non-covalently bound expandable graphite material, such as a non-covalently bound expandable graphite particle.

In a further aspect, a thermoplastic composite comprising a porous core layer comprising a web of an open-celled structure comprising random intersections of reinforcing fibers held together by a thermoplastic material, the porous core layer further comprising: an expanded graphite material; For example, EG particles (dispersed in a web of open cell structure) are described. In some cases, the expandable graphitic material such as EG particles is a non-covalently bound expandable graphite material, such as a non-covalently bound expandable graphite particle.

In another aspect, a thermoplastic composite sheet comprising a porous core layer comprising a plurality of reinforcing fibers and a thermoplastic material, further comprising: an expanded graphite material, such as EG particles (in the cavities of the porous core layer) dispersed, and a shell disposed on at least one surface of the porous core layer). In some forms, the expandable graphite material is a non-covalently bonded expandable graphite material, such as non-covalently bonded expandable graphite particles.

In a further aspect, a thermoplastic composite sheet comprising a porous core layer comprising a web of an open-celled structure comprising random crossings of reinforcing fibers held together by a thermoplastic material, the porous core layer further comprising: an expanded graphite material; For example, EG particles (dispersed in a web of open cell structure, and a shell disposed on at least one surface of a porous core layer) are provided. In some embodiments, the expandable graphite material is a non-covalently bonded expandable graphite material, such as non-covalently bonded expandable graphite particles.

In another aspect, a prepreg comprising a web of an open cell structure formed by a plurality of reinforcing fibers held together by a thermoplastic material, a prepreg comprising an expandable graphitic material such as EG particles dispersed in the web of the open cell structure is disclosed. . In certain examples, the expandable graphite material is a non-covalently bonded expandable graphite material, such as non-covalently bonded expandable graphite particles.

In a further aspect, a thermoplastic article comprising a porous core layer comprising a plurality of reinforcing fibers and a thermoplastic material, the porous core layer further comprising: an expanded graphite material, such as EG particles (uniform in the pores of the porous core layer) dispersed, wherein the expandable graphite material such as EG particles are present in an effective amount to allow the article to meet/pass the 1991 Federal Motor Vehicle Safety Standard 302 (FMVSS 302) flammability test). In some examples, the expandable graphite material is a non-covalently bonded expandable graphite material, such as non-covalently bonded expandable graphite particles.

In another aspect, a thermoplastic article comprising a porous core layer comprising a web of an open-celled structure comprising random intersections of reinforcing fibers held together by a thermoplastic material, the porous core layer further comprising: an expanded graphite material, e.g. For example, EG particles (uniformly dispersed in a web of an open cell structure, wherein an expanded graphite material (e.g. EG particles) is used to allow the article to meet/pass the 1991 Federal Motor Vehicle Safety Standard 302 (FMVSS 302) flammability test. is present in an effective amount) is disclosed. In certain cases, the expandable graphite material is a non-covalently bonded expandable graphite material, such as non-covalently bonded expandable graphite particles.

In a further aspect, a thermoplastic composite sheet comprising a porous core layer comprising a plurality of reinforcing fibers and a thermoplastic material, further comprising an expanded graphite material such as EG particles uniformly dispersed in the pores of the porous core layer: expanded graphite Materials, such as EG particles (present in an effective amount to allow the article to meet/pass the 1991 Federal Motor Vehicle Safety Standard 302 (FMVSS 302) flammability test, and disposed on at least one surface of the porous core layer) outer shell) is provided. In certain embodiments, the expandable graphite material is a non-covalently bonded expandable graphite material, such as non-covalently bonded expandable graphite particles.

In another aspect, a porous core layer comprising a web of an open-celled structure comprising random crossings of reinforcing fibers held together by a thermoplastic material, further comprising an expanded graphite material such as EG particles ( wherein the expandable graphite material is present in an amount effective to allow the article to meet/pass the 1991 Federal Motor Vehicle Safety Standard 302 (FMVSS 302) flammability test), and a skin disposed on at least one surface of the porous core layer. A thermoplastic composite sheet including a porous core layer is disclosed. In certain embodiments, the expandable graphite material is a non-covalently bonded expandable graphite material, such as non-covalently bonded expandable graphite particles.

In a further aspect, a method for producing a thermoplastic composite comprising: a plurality of reinforcing fibers, a thermoplastic material and an expandable graphite material, such as EG particles, above the melting point of the thermoplastic material and below the loft onset temperature of the expandable graphite material (e.g. For example, by heating the reinforcing fibers, thermoplastic materials and expandable graphitic materials such as EG particles to a first temperature (below the loft onset temperature of the EG particles).

In certain embodiments, the method includes heating the produced article to a second temperature above the loft onset temperature of: an expandable graphite material, such as EG particles (to loft a thermoplastic article). In another embodiment, the method includes selecting the second temperature to be at least 20 degrees Celsius above the first temperature. In a further embodiment, the method includes selecting the second temperature to be at least 40 degrees Celsius above the first temperature. In a further example, the method includes selecting the second temperature to be at least 60 degrees Celsius above the first temperature.

In another aspect, a method of producing a thermoplastic composite comprising: a plurality of reinforcing fibers, a thermoplastic material and an expandable graphite material, such as EG particles, while avoiding any substantial loft of the expandable graphite material (e.g. (avoiding any substantial loft of the EG particles) by heating the reinforcing fibers, thermoplastic material and expandable graphitic material such as EG particles under first heating conditions to satisfy the thermoplastic material.

In a specific example, the first heating condition includes convection heating. In another example, the method includes heating the produced article under second heating conditions to loft an expandable graphite material, for example, to loft EG particles. In certain embodiments, the second heating condition includes radiation heating, for example when the first heating condition includes convective heating.

Additional features, aspects, examples, forms and embodiments are described in greater detail below.

Brief description of the drawing

Specific embodiments are described with reference to the accompanying drawings below:

1A is an illustration of a prepreg (or core), according to a particular example;

Figure 1B shows hypothetical lofting curves for two different lofting agents, according to a specific example;

Figure 2A is an illustration of two prepregs, according to certain configurations;

Figure 2B is an illustration of a complex formed from two prepregs: Figure 2A coupled together according to a specific embodiment;

Figure 2C is an illustration of a skin disposed on a prepreg, according to a particular example;

3 is an illustration of an article comprising a prepreg (or core) and a shell disposed on the prepreg (or core), according to a particular example;

Figure 4 is an illustration of an article comprising a prepreg (or core) and a skin disposed on each side of the prepreg (or core), according to a particular configuration;

Figure 5 is an illustration of an article comprising a prepreg (or core), a shell disposed on the prepreg (or core), and a decorative layer disposed on the shell, according to a particular example;

Figure 6 is an illustration of an article comprising two prepregs or cores coupled to each other along an intermediate layer, according to a particular example;

Figure 7 is an illustration of an article comprising two prepregs or cores and a shell disposed on one of the prepregs or cores, according to certain configurations;

Figure 8 is an illustration of an article comprising two prepregs or cores and a skin disposed on each prepreg or core, according to a particular form;

9 is an illustration of an article comprising two prepregs or cores coupled to each other through an intermediate layer and a skin disposed on one of the prepregs or cores, according to a particular example;

Figure 10 is an illustration of a strip of material disposed on a prepreg or core, according to certain embodiments;

Figure 11 is a bar graph showing the loft thickness of various specimens as a function of different types of heat and different temperatures, according to certain examples;

Figure 12 includes Table 3, according to certain examples;

Figure 13 includes Table 4, according to certain examples;

Figure 14 is a bar graph showing lofting test results, according to a specific example;

Figure 15 includes Table 6, according to certain examples;

Figure 16 includes Table 7, according to certain examples;

Figure 17 includes Table 8, according to certain implementations; and

Figure 18 is a graph showing expansion ratio as a function of temperature for three different expandable graphite materials, according to a particular example.

Given the benefit of this disclosure, it will be appreciated by those skilled in the art that certain dimensions or features in the figures may be expanded, distorted or shown in an otherwise liberal or non-proportional manner to provide a more user-friendly version of the figures. will be recognized as No specific thickness, width or length is intended by illustration in the figures, and the relative sizes of figure elements are not intended to limit the size of any element in the figures. Where dimensions or values are specified in the description below, the dimensions or values are provided for illustrative purposes only. Additionally, no specific material or arrangement is intended to be required by virtue of shading of specific portions of a figure, and even though different components of a figure may include shading for purposes of differentiation, the different components may be made of the same or similar materials. You can include it if you wish. In some cases, the core layer comprising an expandable graphite material is shown to include stumps or dots for illustrative purposes. The arrangement of stumps and dots is not intended to imply any particular distribution unless otherwise specified in the context of a particular diagram description.

details

Certain embodiments are described below with reference to singular and plural terms to provide a more user-friendly description of the technology disclosed herein. These terms are used for convenience purposes only and are not intended to limit prepregs, cores, articles, composites and other subject matter to the inclusion or exclusion of specific features as they exist in the particular embodiments described herein, unless otherwise indicated.

Certain articles described herein are said to meet the FMVSS 302 test or SAE J369 test standards. These tests are generally equivalent and are used to determine combustion rate measurements. Briefly, the test utilizes a horizontal combustion chamber, an exhaust hood, a tote large enough to handle specimens about 12 inches long, a water source, a timer, a lighter, and a ruler. The sample size is about 4 inches times about 12 inches and five or more specimens are typically tested. The adhesive side of the specimen is typically fired. For FMVSS 302 testing, the exhaust hood is typically opened sufficiently to provide an airflow of approximately 150 cubic feet per minute. For SAE J369 testing, the exhaust hood can be open, for example, to provide equal airflow or can be open in all directions. Unless otherwise indicated herein, the FMVSS 302 test is interchangeable with the SAE J369 test. The results of these tests can be classified in several ways, including DNI, SE/0, SE/NBR, SE/B, B, and RB. DNI refers to a material that does not maintain combustion during or after the 15 second ignition period and/or does not transfer combustion across a surface to a previously selected distance. SE/0 refers to a material that ignites on the surface, but self-extinguishes before the combustion travels the selected distance. SE/NBR refers to a material that stops burning before burning for 60 seconds from the start of timing and does not burn more than approximately 50 mm from the point where timing started. SE/B refers to a leading burn that self-annihilates before reaching the second distance but progresses fully over the selected distance. B refers to materials that burn the entire distance. RB refers to materials that burn so rapidly that it is not possible to time the combustion rate. One or more of the burning distance, burning time, burning speed, and whether the material self-annihilates can also be measured. A specimen may be considered to “meet” or “pass” the FMVSS 302 or SAE J369 tests if the combustion travels less than approximately 102 mm/min. Specimens may fail the test if they burn faster than 102 mm/min.

In certain cases, thermoplastic composites are often molded or machined into various shapes to provide a final formed part or article. During processing, it may be desirable to increase the overall thickness of one or more components or layers of the article to be processed. In some forms described herein, the presence of an expandable graphite material in the thermoplastic prepreg or thermoplastic core allows for changes in the overall thickness of the article (or portion thereof) during heating, forming or other temperature or processing operations. In some cases, the expandable graphite material is dispersed in a substantially uniform distribution from surface to surface, for example, in the cavity of a thermoplastic prepreg or core comprising a thermoplastic material and a plurality of fibers. In certain examples, the expandable graphite material is non-covalently bound to another material in the prepreg or core. In a further example, the expandable graphite material may be covalently bonded to one or more groups present in a thermoplastic material, or may be covalently bonded to one or more groups of a plurality of fibers, or both. The exact lofting temperature used may vary depending on the prepreg, core, and other materials present in the article, and in some cases, the lofting temperature is the melting temperature of the prepreg, core, and thermoplastic material(s) present in the article. It may be above or equal to the temperature.

In certain forms, the articles described herein may include a prepreg or core layer. Without wishing to be bound by any particular theory, prepregs are generally not fully cured or processed versions of the core. For example, a partially cured layer comprising a thermoplastic material, a plurality of fibers and an expandable graphite material is generally referred to as a prepreg, whereas a partially cured layer comprising a thermoplastic material, a plurality of fibers and an expandable graphite material (which may be lofted or The fully cured layer (which may or may not yet be lofted) is generally referred to as the core or core layer. As mentioned herein, although the core may be hardened, the core may be further processed to change its shape or to increase its thickness to provide a formed article or product suitable for the intended use. You can. The description below refers to all prepregs and cores and the materials (and their amounts and properties) used in relation to prepregs may also be used in cores if desired.

In certain forms described herein, an expanded graphite (EG) material is included in the prepreg core and article to provide selective lofting of the prepreg, core, and article. Lofting generally refers to the overall increase in the thickness of a prepreg, core or article during or following the application of processing conditions, such as heat and/or pressure. For example, the EG material is substantially insusceptible to the prepreg, core or article to lofting at a first temperature and/or first heating condition and then to lofting at a second temperature and/or second heating condition. can be selected to be sensitive to In some cases, prepregs, cores and articles comprising EG materials do not loft to a substantial extent under convective heating conditions, whereas prepregs, cores and articles comprising EG materials do loft under infrared heating conditions. In other cases, prepregs, cores and articles containing EG materials do not loft to a substantial extent at a first temperature and then loft to a substantial extent at a second temperature. For example, in certain automotive applications, EG materials may be selected to substantially not loft at 200 degrees Celsius and to loft at 220 degrees Celsius. Without wishing to be bound by any particular theory, the first and second temperatures may vary depending on the prepreg, core, or thermoplastic material present in the article. In certain cases, EG materials are selected such that substantially no loft occurs until the loft temperature is: greater than about 20 degrees Celsius (above the melting point of the thermoplastic material). In other cases, the EG material is selected so that substantially no loft occurs until the loft temperature is: greater than about 40 degrees Celsius (above the melting point of the thermoplastic material). In further cases, the EG material (and/or lofting conditions) are selected such that substantially no loft occurs until the loft temperature is: greater than about 60 degrees Celsius (above the melting point of the thermoplastic material). In some cases, EG materials are selected such that substantially no loft occurs until the loft temperature is: greater than about 80 degrees Celsius (above the melting point of the thermoplastic material).

In some cases, the prepregs, cores and articles described herein are open cell structures, such as porous or permeable materials containing voids. The presence of the open cell structure makes it more difficult to make the prepreg, core and article flame retardant and/or more difficult for the component to self-extinguish as air trapped within the porous structure will remain flammable. By including EG materials in combination with thermoplastic materials and fibers, prepregs, cores and articles can be flame retardant and/or self-extinguishing. For example, a plurality of reinforcing fibers, a thermoplastic material, and an effective amount of expanded graphite to meet the 1991 Federal Motor Vehicle Safety Standard 302 (FMVSS 302) flammability test, which is generally equivalent to ISO 3795, 1989, and ASTM D5132, 2004. An article can be produced that includes a porous core layer containing particles. If desired, the EG material can be uniformly dispersed in the pores of the porous core layer. A skin of other materials may also be disposed on the porous core layer, if desired.

In certain forms, porous prepregs can be produced comprising one or more thermoplastic materials and a plurality of fibers having an open cell structure, for example, pores together. In some forms, the expandable graphite material can be loaded into the void in a manner that the expandable graphite material does not generally covalently bond with the thermoplastic material and/or fibers. For example, thermoplastic materials and/or fibers can be selected so that they are generally inert or non-reactive with the expandable graphite material. Although the expandable graphite material cannot covalently bond to the thermoplastic material and/or fibers, there are typically covalent bonds present on or within the expandable graphite material itself. In other cases, it may be desirable to covalently bond the expandable graphite material to a thermoplastic material, fiber, or both to provide some covalently bonded expandable graphite material in the prepreg. Even when bound expandable graphite material is present, the expandable graphite material can still increase its occupied volume, preferably under suitable conditions such as, for example, radiation heating to allow lofting of the prepreg. In some cases, both covalently bonded expandable graphitic material and non-covalently bonded expandable graphitic material may also be present in the prepreg. Some forms of prepreg may comprise about 100% of the expandable graphitic material non-covalently bound, while weak interactions such as van der Waals' interactions or electrostatic interactions may occur between the expandable graphitic material and the prepreg. It can occur between different components of .

In a specific example and with reference to the following: Figure 1A, prepreg 100 is shown comprising a thermoplastic material and a plurality of fibers. The prepreg 100 also includes an expandable graphite material (shown for illustration purposes as point 105) dispersed throughout the prepreg 100. In some cases, the expandable graphite material dispersion may be substantially homogeneous or substantially uniform from the first surface 102 to the second surface 104 of the prepreg 100. As described in more detail herein, to achieve the substantially homogeneous or substantially uniform distribution of expandable graphite material in prepreg 100, the components of prepreg 100 can be mixed together to form a dispersion. Mixing may be performed until the dispersion comprises a substantially homogeneous or substantially uniform mixture of the expandable graphite material, thermoplastic material and fibers in the dispersion. Prepreg 100 can then be formed by placing the dispersion on a wire screen, for example, using a suitable layering process, as described herein. In another form, it may be desirable to provide a gradient distribution of expandable graphite material from surfaces 102 to surfaces 104 such that more expandable graphite material is present for one of surfaces 102, 104 than for the other surface. In some embodiments, a substantially uniform distribution of expandable graphite material is present in the prepreg 100 and then additional expandable graphite material is added to one of the prepregs 100 to provide a gradient distribution. The additional expandable graphite material may be added directly to the prepreg 100, for example by spraying or coating a solution containing the expandable graphite material, or may be added to the prepreg 100 as a shell, additional prepreg or expandable graphite material. It can be added by coupling other components including. For example and with reference to the following: Figure 2A, a first prepreg 210 and a second prepreg 220 disposed on the first prepreg 210 are shown. Each first prepreg 210 and second prepreg 220 includes a substantially uniform distribution of expandable graphite material, but the amount of expandable graphite material in the prepregs 210, 220 is different. If desired, however, only one prepreg 210, 220 may include an expandable graphite material and the other prepreg may not include a lofting agent or may contain a lofting agent other than an expandable graphite material, e.g., microspheres. It can be included. The microspheres may be present in combination with an expandable graphite material or as one of the prepregs 210, 220 without any expandable graphite material. The thermoplastic material of prepregs 210, 220 can be melted to provide: a single prepreg 250 (Figure 2B). The result of melting prepregs 210, 220 together is a gradient distribution of expandable graphitic material in prepreg 250 with an increased amount of expandable graphitic material adjacent surface 252 when compared to the amount present adjacent surface 254. The exact overall thickness of prepreg 250 may vary depending on the conditions used and no specific thickness is intended to be implied below: Figure 2B.

In another form, the distribution of the expandable graphite material within the prepreg may be provided by coupling the prepreg with another material or shell containing the expandable graphite material. Referring to the following: Figure 2C, a sheath 270 comprising an expandable graphite material is shown disposed on a prepreg 260 comprising a thermoplastic material, reinforcing fibers and an expandable graphite material. Although not required, sheath 270 is typically at a thickness much lower than the pre-lofted thickness of prepreg 260. Additionally, a recognizable interface typically exists between the shell 270 and the interface 260, while the coupling of the two prepregs to each other, as described in connection below: Figure 2B, typically couples last. It does not result in any recognizable interface in the ringed prepreg 250. In other cases, sheath 270 may be melted to prepreg 260 to couple sheath 270 and prepreg 260 to remove the coupled sheath/prepreg composite material without any substantial interface. Additional sheaths, which may or may not include an expandable graphite material, may also be coupled to the prepreg on the opposite side from sheath 270, if desired and as described in more detail below.

In certain forms, the thermoplastic material of the prepreg may be in fiber form, particulate form, resin form, or other suitable form. In some cases, the thermoplastic material used in the prepreg may be in particle form and have an average particle size that is substantially the same as the average particle size of the expandable graphite material. Without wishing to be bound by any particular scientific theory, by matching the particle sizes of the thermoplastic material and the expandable graphite material, improved processing of the prepreg, including, for example, increased retention of the expandable graphite material in the prepreg, may be achieved. You can. In some cases, the average particle size of the expandable graphite material and the average particle size of the thermoplastic material can vary by about 5% to about 10% and improved processing can still be achieved. In certain forms, the average particle size of each thermoplastic material and expandable graphite material in the prepreg may differ by about 50 microns to about 90 microns. In some forms, the average particle size of the expanded graphite is at least 50% of the average particle size of the thermoplastic material particles to provide improved processing. In other cases, an expanded graphite material having an average particle size about the same as that of the thermoplastic material may be present along with an expanded graphite material having an average particle size that is different than the average particle size of the thermoplastic material. Although the average particle size of the expandable graphite material may be different, the chemical composition of the expandable graphite material may be the same or different. In yet another form, there may be two or more thermoplastic materials with different average particle sizes. If desired, there may be two expandable graphite materials having an average particle size that is substantially the same as the average particle size of the thermoplastic material. The two expandable graphite materials may be chemically identical or may be chemically different. Similarly, thermoplastic materials may be chemically identical (but have different average particle sizes) or may be chemically different.

In certain embodiments, the prepreg 100 generally includes a substantial amount of open cell structure such that vacancies are present in the prepreg. For example, the core layer may include the following pore contents or porosity: 0-30%, 10-40%, 20-50%, 30-60%, 40-70%, 50-80%, 60%. -90%, 0-40%, 0-50%,0-60%,0-70%,0-80%,0-90%, 10-50%, 10-60%, 10-70%, 10 -80%, 10-90%, 10-95%, 20-60%, 20-70%, 20-80%, 20-90%, 20-95%, 30-70%, 30-80%, 30 -90%, 30-95%, 40-80%, 40-90%, 40-95%, 50-90%, 50-95%, 60-95% 70-80%, 70-90%, 70- 95%, 80-90%, 80-95% or any exemplary value within these exemplary ranges. In some cases, the prepreg includes a porosity or pore content greater than 0% and is not fully consolidated, for example, to about 95%. Unless otherwise stated, reference to a prepreg with a specific pore content or porosity is based on the total volume of the prepreg and not necessarily the total volume of the prepreg plus any other materials or layers coupled to the prepreg. No.

In certain embodiments, the high porosity present in the prepreg allows entrapment of expandable graphitic material within the pores of the prepreg. For example, an expandable graphitic material can be co-located in a non-covalently bound manner. Application of heat or other small changes may act to increase the volume of the non-covalently bonded expandable graphitic material which in turn increases the overall thickness of the prepreg, e.g. increasing the size of the expandable graphite material and/ Alternatively, the thickness increases as additional air is captured in the prepreg. For example, expandable graphite materials can act as lofting agents such that a suitable stimulus, such as radiant heat, serves to increase the overall thickness of the prepreg. In some cases, expandable graphite materials in prepregs are effective to function as stepped lofting agents. As used herein, stepped lofting or stepped lofting agent refers to a lofting agent whose thickness increases with temperature, then plateaus, and then increases again with increasing temperature. Referring to the examples below: Figure 1B, two hypothetical lofting curves, one curve 150 representing, for example, a linear lofting agent such as a microsphere, and one representing, for example, a stepped lofting agent such as an expandable graphite material. Another curve is shown as 160. The volume of linear lofting agent generally increases linearly as a function of increasing temperature. Many lofting agents, such as microspherical lofting agents, function in a binary manner and the slope tends to steepen as it moves from non-lofted to fully lofted at a particular temperature. In contrast, the volume of a stepped lofting agent generally increases stepwise as a function of temperature. Stepwise increases in volume provide improved control of overall prepreg thickness and reduce the likelihood of over-loft. The desired thickness using prepreg containing expandable graphite material can be achieved by selecting an appropriate processing temperature. If the thickness is insufficient, in many cases higher temperatures can then be applied to increase the overall thickness to the desired thickness.

In certain embodiments, the thermoplastic material of the prepreg described herein is, at least partially, one or more polyethylene, polypropylene, polystyrene, acrylonitrile styrene, butadiene, polyethylene terephthalate, poly butylene terephthalate, polybutylenetetrachlorate, and polyvinyl chloride, and blends of these materials with each other or with other polymeric materials. Other suitable thermoplastics include, but are not limited to: polyarylene ethers, polycarbonates, polyestercarbonates, thermoplastic polyesters, polyimides, polyetherimides, polyamides, acrylonitrile-butylacrylate-styrene. Polymers, amorphous nylon, polyarylene ether ketone, polyphenylene sulfide, polyaryl sulfone, polyether sulfone, liquid crystalline polymer, poly(1,4 phenylene) compound commercially known as PARMAX®, high temperature polycarbonate such as Bayer's APEC® PC, high-temperature nylon, and silicone, as well as alloys and blends of these materials with each other or other polymeric materials. The thermoplastic materials used to form the prepreg may be in powder form, resin form, rosin form, fiber form, or Any other suitable form may be used. Exemplary thermoplastic materials in various forms are described herein and, for example, in U.S. Publication Nos. 20130244528 and US20120065283. The exact amount of thermoplastic material present in the prepreg may vary and an exemplary amount is about 20% by weight. It ranges from about 80% by weight.

In certain examples, the fibers of the prepregs described herein may include: glass fibers, carbon fibers, graphite fibers, synthetic organic fibers, especially high modulus organic fibers such as, for example, para- and meta-aramid fibers. , nylon fibers, polyester fibers, or any of the high melt flow index resins described herein suitable for use as: fibers, natural fibers such as hemp, sisal, jute, flax, coir, kenaf and cellulosic fibers, mineral fibers. such as basalt, mineral wool (e.g., rock wool or slag wool), wollastonite, alumina silica, and the like, or mixtures thereof, metal fibers, metallized natural and/or synthetic fibers, ceramic fibers, yarn fibers, or the like. mixture of In some embodiments, any of the above-mentioned fibers may be treated chemically prior to use to provide desired functional groups or to impart other physical properties to the fibers, for example, whether they are thermoplastic materials, expandable graphite materials, or It can be chemically treated to react with everything. In some cases, the fibers used in the prepreg may first be reacted with an expandable graphite material to provide derived fibers that are then mixed with the thermoplastic material. Alternatively, the expandable graphite material can be reacted with the thermoplastic material of the prepreg to provide a derived thermoplastic material that is then mixed with the fibers. The fiber content in the prepreg may be from about 20% to about 90% by weight of the prepreg, and more particularly from about 30% to about 70% by weight of the prepreg. Typically, the fiber content of a composite comprising prepreg is from about 20% to about 90% by weight of the composite, more particularly from about 30% to about 80% by weight, such as from about 40% to about 70% by weight. Varies. The specific size and/or orientation of the fibers used may depend, at least in part, on the polymer material used and/or the desired properties of the resulting prepreg. Suitable additional types of fibers, fiber sizes and amounts will be readily selected by those skilled in the art, given the benefit of this disclosure. In one non-limiting example, the fibers dispersed within the thermoplastic material and the expandable graphite material to provide the prepreg have a diameter generally greater than about 5 microns, more particularly from about 5 microns to about 22 microns, and from about 5 mm to about 5 mm. has a length of about 200 mm; More specifically, the fiber diameter can be from about micron to about 22 microns and the fiber length can be from about 5 mm to about 75 mm.

In certain instances, the prepreg expandable graphitic material described herein typically includes one or more graphene-based materials present in stacked molecular layers. Without wishing to be bound by any particular theory, in addition to providing lofting ability, expandable graphite materials also provide some degree of flame retardancy. In some embodiments, sufficient expandable graphite material is present, e.g., an amount of flame retardant of the expandable graphite material is present in the prepreg such that the prepreg has a flame retardant of the prepreg, which is generally equivalent to ISO 3795, 1989 and ASTM D5132, 1991, 2004. Meets Federal Motor Vehicle Safety Standard 302 (FMVSS 302) flammability tests. The above flame retardant amounts can allow for the construction of prepregs that are substantially free of external flame retardants.

The exact type of expandable graphite material used in the prepreg can depend on numerous factors, including, for example, the desired lofting temperature and the desired flame retardancy. Exemplary commercially available expandable graphite materials are available from: Nyacol Nano Technologies, Inc. (Ashland, MA) and, for example, Grades 35, 200, 249, 250, 251, KP251 and 351 expandable graphite materials. Additional expandable graphite materials can be purchased commercially from Graftech International (Lakewood, OH). Without wishing to be bound by any particular reaction, expandable graphite materials can generally be produced by acidification of graphite ore. Acidification results in an insertion process in which, for example, sulfuric acid acts as an insertion agent. The solution can then be neutralized to provide a series of layers of sheets of hexagonal carbon-carbon bonded material. The layers are generally flat and interact with additional hexagonal carbon-carbon layers to provide a layered sheet structure. Layered sheet structures can be held together through covalent bonds or electrostatic interactions (or both) between the sheets. Heating the expandable graphite material in the thermoplastic prepregs and cores described herein can result in increased separation between the layers and a resulting increase in the thickness of the prepreg. If desired, the expandable graphite material can be oxidized using a suitable oxidizing agent to form graphene oxide. As mentioned herein, expandable graphite materials can exist in many forms, including flake form, granular form, or other forms. In some cases, the expandable graphite material is in particulate form and may comprise, for example, an average particle size of at least 300 microns.

In some forms, the prepreg may be substantially halogen-free or halogen-free prepreg to meet constraints regarding hazardous materials requirements for particular applications. In other cases, the prepreg is a halogenated flame retardant such as, for example, a halogenated flame retardant comprising one or more of F, Cl, Br, I, and At or a halogen such as tetrabromo bisphenol-A polycarbonate. or compounds containing monohalo-, dihalo-, trihalo-, or tetrahalo-polycarbonates. In some cases, the thermoplastic materials used in the prepreg and core may contain one or more halogens to impart some flame retardancy without the addition of another flame retardant. If a halogenated flame retardant is present, the flame retardant is preferably present in a flame retardant amount, which may vary depending on the other components present. For example, the halogenated flame retardant may be present in an amount of from about 0.1 weight percent to about 15 weight percent (based on the weight of the prepreg), more particularly from about 1 weight percent to about 13 weight percent, such as from about 5 weight percent to about 13 weight percent. It may be present in weight percent. If desired, two different halogenated flame retardants can be added to the prepreg. In other cases, non-halogenated flame retardants such as, for example, flame retardants including one or more of N, P, As, Sb, Bi, S, Se, and Te may be added. In some embodiments, non-halogenated flame retardants can include phosphorylated materials to make the prepreg more environmentally friendly. If a non-halogenated or substantially halogen-free flame retardant is present, the flame retardant is preferably present in a flame retardant amount, which may vary depending on the other components present. For example, the substantially halogen-free flame retardant may be present in an amount of from about 0.1 weight percent to about 15 weight percent (based on the weight of the prepreg), more particularly from about 1 weight percent to about 13 weight percent, e.g., by weight of the prepreg. It may be present from about 5 weight percent to about 13 weight percent. If desired, two different substantially halogen-free flame retardants may be added to the prepreg. In certain cases, prepregs described herein may include one or more halogenated flame retardants in combination with one or more substantially halogen-free flame retardants. When two different flame retardants are present, a combination of the two flame retardants can be present in an amount of flame retardant that can vary depending on the other components present. For example, the total weight of flame retardant present (based on the weight of the prepreg) may be from about 0.1 weight percent to about 20 weight percent, more particularly from about 1 weight percent to about 15 weight percent, e.g., by weight of the prepreg. It may be from about 2 weight percent to about 14 weight percent based on . Flame retardants used in the prepregs described herein may be added to the mixture comprising the expanded graphite material, thermoplastic material and fibers (prior to processing the mixture on a wire screen or other processing component) or may be added after the prepreg is formed. there is.

In certain forms, the articles described herein may include a porous core. In certain examples, the porous core includes one or more thermoplastic materials and a plurality of fibers that may instead be held by the thermoplastic material hardened in a web or network structure to provide a plurality of open cells, pores, or webs in the core. In some cases, the expandable graphite material may be present in the cavities of the core in a manner that the expandable graphite material would not normally be covalently bonded to the thermoplastic material and/or fibers. For example, thermoplastic materials and/or fibers can be selected so that they are generally inert or non-reactive with the expandable graphite material. Although the expandable graphite material is not capable of covalently bonding to the thermoplastic material and/or fiber, there are typically covalent bonds present at or within the expandable graphite material itself, for example, layers of the expandable graphite material can be bonded to each other via one or more intervening drugs. It can be related. In other cases, it may be desirable to covalently bond the expandable graphite material to the thermoplastic material, fibers, or both to provide some covalently bonded expandable graphite material in the core. Even if bound expandable graphitic material is present in the core, the expandable graphitic material can preferably still increase its occupied volume under suitable conditions such as, for example, radiation heating to allow lofting of the core. In some cases, all covalently bonded expandable graphitic material and non-covalently bonded expandable graphitic material may also be present in the core. Some forms of the core may include an expanded graphitic material in which approximately 100% of the expanded graphitic material is non-covalently bound, while weak interactions such as van der Waals' interactions or electrostatic interactions may occur between the expanded graphitic material and other components of the core. may occur between the components, for example charge-charge interactions or hydrophobic interactions may occur between the various components present in the core.

In certain forms, cores similar to the following prepregs may be produced: Figure 1. The core includes an expandable graphite material dispersed throughout the core. In some cases, the expandable graphite material dispersion may be substantially homogeneous or substantially uniform from the first surface to the second surface of the core. As described in more detail herein, to achieve the substantially homogeneous or substantially uniform distribution of expandable graphite material in the core, the components of the core may be mixed together to form a dispersion. Mixing may be performed until the dispersion comprises a substantially homogeneous or substantially uniform mixture of the expandable graphite material, thermoplastic material and fibers in the dispersion. The core may then be formed as described herein, for example, by placing the dispersion on a wire screen using a suitable layering process followed by curing the thermoplastic material of the core. In another form, it may be desirable to provide a gradient distribution of the expandable graphite material from one surface of the core to another surface of the core. In some forms, a substantially uniform distribution of expandable graphite material is present in the cores and then additional expandable graphite material is added to one of the cores to provide a gradient distribution. The additional expandable graphite material may be added directly to the core, for example by spraying or coating a solution containing the expandable graphite material, or may be added to the core, including a skin, additional prepreg or core or the expandable graphite material. It can be added by coupling other components. For example, a first core and a second core disposed on the first core can provide a composite product. Each core may include a substantially uniform distribution of expandable graphite material, but the amount and/or type of expandable graphite material in the two cores may be different, for example, the loading rate may be different, or The materials themselves may be different. If desired, however, only one core may include an expandable graphite material and the other core may not include a lofting agent or may include a lofting agent other than the expandable graphite material, for example, microspheres. The microspheres may be present in combination with an expandable graphite material or may be present in one of the cores without any expandable graphite material. The thermoplastic material of the core may be melted to provide a single combined core containing material from two cores. The result of melting of the core is a composite core with a gradient distribution of expandable graphite material. In another form, the distribution of the expandable graphitic material in the core may be provided by coupling a shell or other material comprising the expandable graphite material to the core. In other cases, the shell may be melted to the core to couple the shell and core to remove the coupled shell/core composite material without any substantial interface. If desired and as described in more detail below, an additional shell, which may or may not comprise an expandable graphite material, can also be coupled to the core on the side opposite from the first shell.

In certain embodiments, the thermoplastic material of the core may be used to provide the core in fiber form, particulate form, resin form, or other suitable form. In some examples, the thermoplastic material used in the core may exist in particle form and have an average particle size that is substantially the same as the average particle size of the expandable graphite material. By matching the particle sizes of the thermoplastic material and the expandable graphite material, improved processing of the core can be achieved, including, for example, increased retention of the expandable graphite material in the core, an increase in preserved loft capacity, etc. In some cases, the average particle size of the expandable graphite material and the average particle size of the thermoplastic material can vary by about 5% to about 10% and improved processing can still be achieved. In certain forms, the average particle size of each thermoplastic and expandable graphite material in the core may range from about 50 microns to about 900 microns. In other cases, an expanded graphite material having an average particle size about the same as that of the thermoplastic material may be present along with an expanded graphite material having an average particle size that is different than the average particle size of the thermoplastic material. Although the average particle size of the expandable graphite material may be different, the chemical composition of the expandable graphite material may be the same or different. In yet another form, there may be two or more thermoplastic materials with different average particle sizes. If desired, two expandable graphite materials may be present in the core having an average particle size that is substantially the same as the average particle size of the two thermoplastic materials. The two expandable graphite materials may be chemically identical or may be chemically different. Similarly, thermoplastic materials may be chemically identical (but have different average particle sizes) or may be chemically different.

In certain embodiments, the core generally includes a substantial amount of open cell structure such that vacancies are present in the core. For example, the core layer may include the following pore contents or porosity: 0-30%, 10-40%, 20-50%, 30-60%, 40-70%, 50-80%, 60%. -90%, 0-40%, 0-50%,0-60%,0-70%,0-80%,0-90%, 5-30%, 5-40%, 5-50%, 5 -60%, 5-70%, 5-80%, 5-90%, 5-95%, 10-50%, 10-60%, 10-70%, 10-80%, 10-90%, 10 -95%, 20-60%, 20-70%, 20-80%, 20-90%, 20-95%, 30-70%, 30-80%, 30-90%, 30-95%, 40 -80%, 40-90%, 40-95%, 50-90%, 50-95%, 60-95% 70-80%, 70-90%, 70-95%, 80-90%, 80- 95% or any exemplary value within these exemplary ranges. In some cases, the core includes a porosity or pore content greater than 0% and is not fully consolidated, for example, to about 95%. Unless otherwise stated, references to a core containing a specific pore content or porosity are based on the total volume of the core and not necessarily the total volume of the core plus any other materials or layers coupled to the core. Compared to prepreg, the porosity of the core may be the same or may be different. For example, in many cases, the prepreg is formed into a core by passing the prepreg through a set of rollers or by passing one surface of the prepreg. In such cases, the porosity of the core may be different, for example lower, than the porosity of the prepreg. In some cases, the porosity of the core is intentionally selected to be less than a comparable prepreg to provide increased lofting of the core in the final formed article or product.

In certain embodiments, the high porosity present in the core allows entrapment of expandable graphitic material within the pores of the core. For example, an expandable graphitic material can be co-located in a non-covalently bound manner. The application of heat or other small changes may act to increase the volume of the non-covalently bound expandable graphitic material which in turn increases the overall thickness of the core, e.g. as the size of the expandable graphitic material increases, the graphite The thickness increases as the separation distance between the molecular layers of the material increases and/or as additional air is captured in the core. For example, an expandable graphite material can act as a lofting agent such that a suitable stimulus, such as radiant heat, acts to increase the overall thickness of the core. As mentioned herein, the stimulation can increase core thickness by increasing the separation distance between layers of expandable graphite material and/or by entrapment of air within the post-lofted core structure. In some cases, the expandable graphite material in the core is effective to function as a stepped lofting agent as related below: Figure 1B and the prepreg description herein. As demonstrated in the examples appended herein, cores comprising expandable graphite materials can provide improved lofting capacity due to the generally insensitive core (compared to microspheres) to lower convective heating temperatures. For example, a prepreg of expandable graphite material can be machined into the core without substantial expansion of the expandable graphite material. The pre-lofting capacity allows the end user to further machine the core to provide the article or component with a desired thickness and/or shape. In contrast, prepregs containing microspheres machined into the core typically experience some expansion (and potential collapse of the microspheres) during processing into the core. This expansion can reduce the remaining expansion available and limit the overall thickness achievable in the final formed article.

In certain embodiments, the thermoplastic material of the core described herein may, at least in part, include: one or more of polyethylene, polypropylene, polystyrene, acrylonitrile styrene, butadiene, both plasticized and unplasticized. , polyethylene terephthalate, polybutylene terephthalate, polybutylenetetrachlorate, and polyvinyl chloride, and blends of these materials with each other or with other polymeric materials. Other suitable thermoplastics include, but are not limited to: : Polyarylene ether, polycarbonate, polyester carbonate, thermoplastic polyester, polyimide, polyetherimide, polyamide, acrylonitrile-butylacrylate-styrene polymer, amorphous nylon, polyarylene ether ketone, polyphenylene. sulfides, polyaryl sulfones, polyether sulfones, liquid crystalline polymers, poly(1,4 phenylene) compounds commercially known as PARMAX®, high temperature polycarbonates such as Bayer's APEC® PC, high temperature nylon, and silicone, as well as each other. or alloys and blends of these materials with other polymeric materials. The thermoplastic material used to form the core may be in powder form, resin form, rosin form, fiber form or other suitable form. Exemplary thermoplastic materials in various forms are described herein and, for example, in US Publication Nos. 20130244528 and US20120065283. The exact amount of thermoplastic material present in the core may vary and exemplary amounts range from about 20% by weight to about 80% by weight.

In certain examples, the fibers of the core described herein may include: glass fibers, carbon fibers, graphite fibers, synthetic organic fibers, especially high modulus organic fibers such as, for example, para- and meta-aramid fibers, Nylon fibers, polyester fibers, or any of the high melt flow index resins described herein are suitable for use as: fibers, natural fibers such as hemp, sisal, jute, flax, coir, kenaf and cellulosic fibers, mineral fibers such as Basalt, mineral wool (e.g., rock wool or slag wool), wollastonite, alumina silica, and the like, or mixtures thereof, metal fibers, metallized natural and/or synthetic fibers, ceramic fibers, yarn fibers, or their mixture. In some embodiments, any of the above-mentioned fibers may be treated chemically prior to use to provide desired functional groups or to impart other physical properties to the fibers, for example, whether they are thermoplastic materials, expandable graphite materials, or It can be treated chemically to react with everything. In some cases, the fibers used in the core may first be reacted with an expandable graphite material to provide derived fibers that are then mixed with the thermoplastic material. Alternatively, the expandable graphite material can be reacted with the thermoplastic material of the core to provide a derived thermoplastic material that is then mixed with the fibers. The fiber content in the core may be from about 20% to about 90% by weight of the core, more particularly from about 30% to about 70% by weight of the core. The specific size and/or orientation of the fibers used may depend, at least in part, on the polymer material used and/or the desired properties of the resulting core. Suitable additional types of fibers, fiber sizes and amounts will be readily selected by those skilled in the art, given the benefit of this disclosure. In one non-limiting example, the fibers dispersed within the thermoplastic material and the expandable graphite material to provide the core have a diameter generally greater than about 5 microns, more particularly from about 5 microns to about 22 microns, and from about 5 mm to about 22 microns. has a length of 200 mm; More specifically, the fiber diameter can be from about micron to about 22 microns and the fiber length can be from about 5 mm to about 75 mm.

In certain examples, the expandable graphite material of the core described herein includes one or more graphene-based materials. In addition to providing lofting capabilities, expandable graphite materials can also provide some degree of flame retardancy to the core and/or any article comprising the core. In some embodiments, sufficient expandable graphite material is present, e.g., the flame retardant amount of the expandable graphite material is such that the core complies with the 1991 Federal Motor Vehicle Safety Standard 302 (which is generally equivalent to ISO 3795, 1989 and ASTM D5132, 2004). FMVSS 302) is present in the core to the extent that it meets the flammability test. The above flame retardant amounts can allow construction of the core substantially free of external or added flame retardants. The size of the expandable graphite material may be selected such that the amount of flame retardant in the expandable graphite material is maintained during processing to form the core. For example, when microspheres are used as a lofting agent, a substantial amount, for example 30% or more of the microspheres, is often removed during processing to form the core. This removal reduces the potential lofting capacity. Improved retention of the expandable graphite material in the core can be achieved if an appropriately sized expandable graphite material is used, for example, an expandable graphite material with an average particle size of about 300 microns or greater. The exact type of expandable graphite material used in the core may depend on numerous factors, including, for example, desired lofting temperature, desired degree of flame retardancy, desired basis weight, and other factors. Exemplary commercially available expandable graphite materials that may be present in the core are commercially available from: Nyacol Nano Technologies, Inc. (Ashland, MA) and, for example, Grades 35, 200, 249, 250, 251, KP251 and 351 expandable graphite materials. Additional expandable graphite materials can be purchased commercially from Graftech International (Lakewood, OH). The expanded graphitic material present in the core generally exists as stacked molecular layers. Heating the expandable graphite material in the thermoplastic core described herein can result in increased separation between the layers and a resulting increase in the thickness of the core. Expandable graphite materials can exist in many forms, including flake form, granular form, or other forms. In some cases, the expandable graphitic material in the core is in the form of flakes or particles and, for example, may comprise an average particle size of at least 300 microns or an average particle size that is substantially similar to the average particle size of the thermoplastic material in the core. may include.

In some cases, the core may be substantially halogen-free or halogen-free core to meet constraints regarding hazardous materials requirements for particular applications. In other cases, the core may comprise: a halogenated flame retardant such as, for example, a halogenated flame retardant comprising one or more of F, Cl, Br, I, and At or a compound comprising such halogens, e.g. , tetrabromo bisphenol-A polycarbonate or monohalo-, dihalo-, trihalo- or tetrahalo-polycarbonate. In some cases, the thermoplastic material used in the core may contain one or more halogens to impart some flame retardancy without the addition of another flame retardant. If a halogenated flame retardant is present, the flame retardant is preferably present in a flame retardant amount, which may vary depending on the other components present. For example, the halogenated flame retardant may be present in an amount of from about 0.1 weight percent to about 15 weight percent (based on the weight of the core), more particularly from about 1 weight percent to about 13 weight percent, such as from about 5 weight percent to about 13 weight percent. It can exist as a percentage. If desired, two different halogenated flame retardants can be added to the core. In other cases, non-halogenated flame retardants such as, for example, flame retardants including one or more of N, P, As, Sb, Bi, S, Se, and Te may be added. In some embodiments, the non-halogenated flame retardant may include a phosphorylated material to make the core more environmentally friendly. If a non-halogenated or substantially halogen-free flame retardant is present, the flame retardant is preferably present in a flame retardant amount, which may vary depending on the other components present. For example, the substantially halogen-free flame retardant may be present in an amount of from about 0.1 weight percent to about 15 weight percent (based on the weight of the core), more particularly from about 1 weight percent to about 13 weight percent, e.g., based on the weight of the core. It may be present from about 5 weight percent to about 13 weight percent. If desired, two different substantially halogen-free flame retardants may be added to the core. In certain cases, the cores described herein may include one or more halogenated flame retardants in combination with one or more substantially halogen-free flame retardants. When two different flame retardants are present, a combination of the two flame retardants can be present in an amount of flame retardant that can vary depending on the other components present. For example, the total weight of flame retardant present may be from about 0.1 weight percent to about 20 weight percent (based on the weight of the core), more particularly from about 1 weight percent to about 15 weight percent, e.g., based on the weight of the core. It can be from about 2 weight percent to about 14 weight percent. Flame retardants used in the cores described herein can be added to a mixture comprising expanded graphite material, thermoplastic material and fibers (prior to processing the mixture on a wire screen or other processing component) or after the core has hardened, e.g. For example, it can be added by soaking the core in flame retardant or spraying the flame retardant onto the core.

In certain embodiments, the prepreg or core described herein may include one or more shells disposed on the surface of the prepreg or core to provide an article. 3, article 300 includes a prepreg or core 310 comprising a thermoplastic material, a plurality of fibers, and an expandable graphite material disposed in a cavity of the prepreg or core. Article 300 includes a first skin 320 disposed on a prepreg or core 310. Shell 320 may include, for example, a film (e.g., a thermoplastic or elastomer film), a prim, a scrim (e.g., a fiber-based scrim), a foil, a fabric, a non-woven fabric, or a prepreg or core 310 It may be present as an inorganic coating, an organic coating, or a thermoset coating disposed on the coating. In other cases, the shell 320 may comprise a limiting oxygen index greater than about 22, as measured according to ISO 4589, 1996. When a thermoplastic film is present as (or as part of) a shell 320, the thermoplastic film includes at least one poly(ether imide), poly(ether ketone), poly(ether-ether ketone), poly(phenylene sulfide), poly (arylene sulfone), poly(ether sulfone), poly(amide-imide), poly(1,4-phenylene), polycarbonate, nylon, and silicone. When a fiber-based scrim is present as (or as part of) sheath 320, the fiber-based scrim may include at least one of glass fiber, aramid fiber, graphite fiber, carbon fiber, inorganic mineral fiber, metal fiber, metallized synthetic fiber, and metal. It may contain converted inorganic fibers. If a thermoset coating is present as (or as part of) the shell 320, the coating may include at least one unsaturated polyurethane, vinyl ester, phenolic, and epoxy. If an inorganic coating is present as (or as part of) the shell 320, the inorganic coating may include a mineral containing a cation selected from Ca, Mg, Ba, Si, Zn, Ti and Al, or at least one gypsum , may include deoxidized calcium and mortar. When a nonwoven fabric is present as (or as part of) the sheath 320, the nonwoven fabric may include thermoplastic materials, thermoset binders, inorganic fibers, metal fibers, metallized inorganic fibers, and metallized synthetic fibers. The prepreg or core 310 may be any of the materials described herein in relation to prepregs and cores, such as thermoplastic materials, reinforcing fibers, and expandable graphitic materials dispersed in the prepreg or core 310, such as prepregs or cores. It may include an expandable graphite material dispersed in a substantially uniform distribution from one surface of the 310 to another surface. If desired, shell 320 may also include an expandable graphite material.

In certain forms, the prepregs and cores described herein can be used to provide articles including a skin on each side of the prepreg or core. 4, an article 400 comprising a prepreg or core 410, a first skin 420 disposed on a first surface of the prepreg or core 410 and a second skin 430 disposed on the prepreg or core 410. It is shown. The prepreg or core 410 may be any of the materials described herein in relation to prepregs and cores, such as thermoplastic materials, reinforcing fibers, and expandable graphitic materials dispersed in the prepreg or core 410, such as prepregs or cores. It may include an expandable graphite material dispersed in a substantially uniform distribution from one surface of the 410 to another surface. Each of the first sheath 420 and the second sheath 430 may be independently selected from a film (e.g., a thermoplastic or elastomeric film), a prim, a scrim (e.g., a fiber-based scrim), a foil, a fabric, a non-woven fabric, or or as an inorganic coating, organic coating, or thermoset coating disposed on the prepreg or core 410. In other cases, shell 420 or shell 430 (or both) may comprise a limiting oxygen index greater than about 22, as measured according to ISO 4589, 1996. When the thermoplastic film is present as (or as part of) the shell 420 or the shell 430 (or both), the thermoplastic film has at least one poly(ether imide), poly(ether ketone), poly(ether-ether ketone), poly (phenylene sulfide), poly(arylene sulfone), poly(ether sulfone), poly(amide-imide), poly(1,4-phenylene), polycarbonate, nylon, and silicone. When a fiber-based scrim is present as (or as part of) the sheath 420 or sheath 430 (or both), the fiber-based scrim comprises at least one of glass fiber, aramid fiber, graphite fiber, carbon fiber, inorganic mineral fiber, metal fiber, metal. It may include metallized synthetic fibers, and metallized inorganic fibers. If a thermoset coating is present as (or as part of) the shell 420 or the shell 430 (or both), the coating may include at least one unsaturated polyurethane, vinyl ester, phenolic, and epoxy. When the inorganic coating is present as (or as part of) the shell 420 or the shell 430 (or both), the inorganic coating may comprise a mineral containing cations selected from Ca, Mg, Ba, Si, Zn, Ti and Al. or may include at least one of gypsum, calcium deoxidation, and mortar. When the nonwoven fabric is present as (or as part of) sheath 420 or sheath 430 (or both), the nonwoven fabric may include thermoplastic materials, thermoset binders, inorganic fibers, metal fibers, metallized inorganic fibers, and metallized synthetic fibers. there is. If desired, one or both of the shells 420, 430 may also include an expandable graphite material.

In certain cases, the article may include a prepreg or core, at least one skin disposed on the prepreg or core, and a decorative or cover layer disposed on the skin. Referring below: Figure 5, an article 500 is shown comprising a prepreg or core 510, a shell 520 disposed on a first surface of the prepreg or core 510, and a decorative layer 530 disposed on the shell 520. The prepreg or core 510 may be any of the materials described herein in relation to prepregs and cores, such as thermoplastic materials, reinforcing fibers, and expandable graphitic materials dispersed in the prepreg or core 510, such as prepregs or cores. It may include an expandable graphite material dispersed in a substantially uniform distribution from one surface of the 510 to another surface. Shell 520 may include, for example, a film (e.g., a thermoplastic or elastomeric film), a prim, a scrim (e.g., a fiber-based scrim), a foil, a fabric, a non-woven fabric, or a prepreg or core 510 Disposed thereon may be an inorganic coating, an organic coating, or a thermoset coating. In other cases, the shell 520 may comprise a limiting oxygen index greater than about 22, as measured according to ISO 4589, 1996. If a thermoplastic film is present, the thermoplastic film may include at least one poly(ether imide), poly(ether ketone), poly(ether-ether ketone), poly(phenylene sulfide), poly(arylene sulfone), poly( ether sulfone), poly(amide-imide), poly(1,4-phenylene), polycarbonate, nylon, and silicone. If a fiber-based scrim is present, the fiber-based scrim may include at least one of glass fibers, aramid fibers, graphite fibers, carbon fibers, inorganic mineral fibers, metal fibers, metallized synthetic fibers, and metallized inorganic fibers. there is. If a thermoset coating is present, the coating may include at least one unsaturated polyurethane, vinyl ester, phenolic, and epoxy. If an inorganic coating is present, the inorganic coating may comprise minerals containing cations selected from Ca, Mg, Ba, Si, Zn, Ti and Al or may comprise at least one of gypsum, calcium deoxidation and mortar. You can. When present, nonwovens may include thermoplastic materials, thermoset binders, inorganic fibers, metal fibers, metallized inorganic fibers, and metallized synthetic fibers. Decorative layer 530 may be formed from a thermoplastic film, for example, polyvinyl chloride, polyolefin, thermoplastic polyester, thermoplastic elastomer, etc. Decorative layer 530 may also be a multi-layered structure comprising a foam core formed from, for example, polypropylene, polyethylene, polyvinyl chloride, polyurethane, etc. The fabric may be bonded to a foam core, such as fabrics made from natural and synthetic fibers, needle punched, etc., followed by organic fiber nonwovens, raised fabrics, knitted fabrics, straight wool fabrics, or other such materials. The fabric can also be bonded to the foam core with thermoplastic adhesives, including pressure sensitive adhesives and hot melt adhesives such as polyamides, modified polyolefins, urethanes and polyolefins. Decorative layer 530 can also be produced using spunbond, heat bonded, spunlace, melt-blown, wet, and/or dry processes.

In certain forms, two or more prepregs or cores may be coupled to each other through an intervening or intermediate layer such as, for example, a skin. Referring to the following: Figure 6, an article 600 is shown comprising a prepreg or core 610 coupled to a prepreg or core 630 via an intermediate layer 620. Each prepreg or core 610, 630 may be the same or different. In some cases, the thermoplastic material and fibers of the prepreg or cores 610, 630 are the same, but the type of expandable graphite material or load of expandable graphite material present in the prepreg or cores 610, 630 is different. In other cases, the type and/or amount of expandable graphite material in the prepreg or core 610, 630 may be the same and one or both of the thermoplastic materials and/or fibers may be different, for example, chemically different. or may be present in different amounts. In some cases, covalently bonded expandable graphitic material may be present in one or more of the prepreg or core 610, 630. In other cases, non-covalently bound expandable graphitic material may be present in one or both prepregs or cores 610, 630. If desired, one or more suitable flame retardants, such as halogenated or non-halogenated flame retardants, may be present in one or both cores 610, 630. While the thickness of the prepregs or cores 610, 630 is shown to be approximately the same in Figure 6, the thickness of the prepregs or cores 610, 630 can vary. In some forms, one of the prepregs or cores 610, 630 may include a lofting agent other than an expandable graphite material, such as microspheres. The microspheres may be present in combination with an expandable graphite material or may be present in one of the prepregs or cores 610, 630 without any expandable graphite material. Interlayer 620 may take the form of a shell as described herein. For example, interlayer 620 may include, for example, a film (e.g., a thermoplastic or elastomeric film), a prim, a scrim (e.g., a fiber-based scrim), a foil, a fabric, a non-woven fabric, or a prep. It may be present as an inorganic coating, an organic coating, or a thermoset coating disposed on the legs or core 610. In other cases, layer 620 may include a limiting oxygen index greater than about 22, as measured according to ISO 4589, 1996. If a thermoplastic film is present, the thermoplastic film may include at least one poly(ether imide), poly(ether ketone), poly(ether-ether ketone), poly(phenylene sulfide), poly(arylene sulfone), poly( ether sulfone), poly(amide-imide), poly(1,4-phenylene), polycarbonate, nylon, and silicone. When a fiber-based scrim is present as or in layer 620, the fiber-based scrim is comprised of at least one of glass fibers, aramid fibers, graphite fibers, carbon fibers, inorganic mineral fibers, metal fibers, metallized synthetic fibers, and metallized fibers. may contain inorganic fibers. If a thermoset coating is present as or in layer 620, the coating may include at least one unsaturated polyurethane, vinyl ester, phenolic, and epoxy. If an inorganic coating is present as or in layer 620, the inorganic coating may include minerals containing cations selected from Ca, Mg, Ba, Si, Zn, Ti and Al, or at least one gypsum, May contain deoxidized calcium and mortar. When a nonwoven fabric is present as or in layer 620, the nonwoven fabric may include thermoplastic materials, thermoset binders, inorganic fibers, metal fibers, metallized inorganic fibers, and metallized synthetic fibers. While not shown, the decoration layer may be coupled to either (or both) the prepreg or cores 610, 630. As mentioned herein, the decorative layer can be formed from thermoplastic films, for example, polyvinyl chloride, polyolefin, thermoplastic polyester, thermoplastic elastomer, etc. The decorative layer can also be a multi-layered structure comprising a foam core formed, for example, from polypropylene, polyethylene, polyvinyl chloride, polyurethane, etc. The fabric may be bonded to a foam core, such as fabrics made from natural and synthetic fibers, needle punched, etc., followed by organic fiber nonwovens, raised fabrics, knitted fabrics, straight wool fabrics, or other such materials. The fabric can also be bonded to the foam core with thermoplastic adhesives, including pressure sensitive adhesives and hot melt adhesives such as polyamides, modified polyolefins, urethanes and polyolefins. Decorative layers can also be produced using spunbond, heat bonded, spunlace, melt-blown, wet, and/or dry processes.

In certain embodiments, two or more prepregs or cores can be coupled to each other and a skin can then be placed on the surface of one of the prepregs or cores. With reference to the following: Figure 7, an article 700 is shown comprising a prepreg or core 710 coupled to a prepreg or core 730 and a shell 720 disposed on the core 730. Each prepreg or core 710, 720 may be the same or different. In some cases, the thermoplastic material and fibers of the cores 710, 730 are the same, but the type of expandable graphite material or load of expandable graphite material present in the cores 710, 730 is different. In other cases, the type and/or amount of expandable graphite material in the cores 710, 730 may be the same and one or both of the thermoplastic materials and/or fibers may be different, for example, chemically different, or It can exist in quantity. In some cases, covalently bonded expandable graphitic material may be present in one or more of the prepreg or core 710, 730. In other cases, non-covalently bound expandable graphitic material may be present in one or both prepregs or cores 710, 720. If desired, one or more suitable flame retardants, such as halogenated or non-halogenated flame retardants, may be present in one or both of the prepreg or core 710, 730. While the thickness of the prepregs or cores 710, 730 is shown to be approximately the same in Figure 7, the thickness of the prepregs or cores 710, 730 can vary. In some forms, one of the prepregs or cores 710, 730 may include a lofting agent other than an expandable graphite material, such as microspheres. The microspheres may be in combination with an expandable graphite material or may be present in one of the prepregs or cores 710, 730 without any expandable graphite material. Shell 720 may include, for example, a film (e.g., a thermoplastic or elastomer film), a prim, a scrim (e.g., a fiber-based scrim), a foil, a fabric, a non-woven fabric, or a prepreg or core 730 It may be present as an inorganic coating, an organic coating, or a thermoset coating disposed on the coating. In other cases, the shell 720 may comprise a limiting oxygen index greater than about 22, as measured according to ISO 4589, 1996. When the thermoplastic film is present as or in a sheath 720, the thermoplastic film has at least one poly(ether imide), poly(ether ketone), poly(ether-ether ketone), poly(phenylene sulfide), poly( arylene sulfone), poly(ether sulfone), poly(amide-imide), poly(1,4-phenylene), polycarbonate, nylon, and silicone. When a fiber-based scrim is present as or in the sheath 720, the fiber-based scrim is comprised of at least one of glass fibers, aramid fibers, graphite fibers, carbon fibers, inorganic mineral fibers, metal fibers, metallized synthetic fibers, and metallized fibers. may contain inorganic fibers. If a thermoset coating is present as or in the shell 720, the coating may include at least one unsaturated polyurethane, vinyl ester, phenolic, and epoxy. If an inorganic coating is present as or in the shell 720, the inorganic coating may include minerals containing cations selected from Ca, Mg, Ba, Si, Zn, Ti and Al, or at least one gypsum, May contain deoxidized calcium and mortar. When a nonwoven fabric is present as or in a sheath 720, the nonwoven fabric may include thermoplastic materials, thermoset binders, inorganic fibers, metal fibers, metallized inorganic fibers, and metallized synthetic fibers. While not shown, the decoration layer may be coupled to the surface of the shell 720 or the prepreg or core 710. As mentioned herein, the decorative layer can be formed from thermoplastic films, for example, polyvinyl chloride, polyolefin, thermoplastic polyester, thermoplastic elastomer, etc. The decorative layer can also be a multi-layered structure comprising a foam core formed, for example, from polypropylene, polyethylene, polyvinyl chloride, polyurethane, etc. The fabric may be bonded to a foam core, such as fabrics made from natural and synthetic fibers, needle punched, etc., followed by organic fiber nonwovens, raised fabrics, knitted fabrics, straight wool fabrics, or other such materials. The fabric can also be bonded to the foam core with thermoplastic adhesives, including pressure sensitive adhesives and hot melt adhesives such as polyamides, modified polyolefins, urethanes and polyolefins. Decorative layers can also be produced using spunbond, heat bonded, spunlace, melt-blown, wet, and/or dry processes.

In certain embodiments, two or more prepregs or cores can be coupled to each other and a skin can then be placed on each surface of the prepregs or cores. 8, an article 800 comprising a prepreg or core 810 coupled to a prepreg or core 830, a first shell 820 disposed on the core 830, and a second shell 840 disposed on the core 810. It is shown. Each prepreg or core 810, 830 may be the same or different. In some cases, the thermoplastic material and fibers of the prepreg or cores 810, 830 are the same, but the type of expandable graphitic material or load of expandable graphitic material present in the prepreg or cores 810, 830 is different. In other cases, the type and/or amount of expandable graphite material in the prepreg or core 810, 830 may be the same and one or both of the thermoplastic materials and/or fibers may be different, for example, chemically different. may be present or may be present in different amounts. In some cases, covalently bonded expandable graphitic material may be present in one or more of the prepreg or core 810, 830. In other cases, non-covalently bound expandable graphitic material may be present in one or both prepregs or cores 810, 830. If desired, one or more suitable flame retardants, such as halogenated or non-halogenated flame retardants, may be present in one or both of the prepreg or cores 810, 830. While the thickness of the prepreg or cores 810, 830 is shown to be approximately the same in Figure 8, the thickness of the prepreg or cores 810, 830 can vary. In some forms, one of the prepregs or cores 810, 830 may include a lofting agent other than an expandable graphite material, such as microspheres. The microspheres may be present in combination with an expandable graphite material or may be present in one of the cores 810, 830 without any expandable graphite material. Each shell 820, 840 may independently include, for example, a film (e.g., a thermoplastic or elastomeric film), a prim, a scrim (e.g., a fiber-based scrim), a foil, a fabric, a non-woven fabric, or or as an inorganic coating, organic coating, or thermoset coating disposed on a prepreg or core 830. In other cases, the shells 820, 840 may independently comprise a limiting oxygen index greater than about 22, as determined according to ISO 4589, 1996. When the thermoplastic film is present as sheath 820 or sheath 840 (or both) or in sheath 820 or sheath 840 (or both), the thermoplastic film comprises at least one poly(ether imide), poly(ether ketone), poly(ether) -ether ketone), poly(phenylene sulfide), poly(arylene sulfone), poly(ether sulfone), poly(amide-imide), poly(1,4-phenylene), polycarbonate, nylon, and silicone. may include. When the fiber-based scrim is present as shell 820 or shell 840 (or both) or in shell 820 or shell 840 (or both), the fiber-based scrim is comprised of at least one glass fiber, aramid fiber, graphite fiber, carbon fiber, or inorganic mineral. Can include fibers, metal fibers, metallized synthetic fibers, and metallized inorganic fibers. When the thermoset coating is present as shell 820 or shell 840 (or both) or on shell 820 or shell 840 (or both), the coating comprises at least one unsaturated polyurethane, vinyl ester, phenolic and epoxy. can do. If the inorganic coating is present as the shell 820 or the shell 840 (or both) or on the shell 820 or the shell 840 (or both), the inorganic coating may contain cations selected from Ca, Mg, Ba, Si, Zn, Ti and Al. It may contain minerals or may contain at least one of gypsum, calcium deoxidation and mortar. When the nonwoven is present as sheath 820 or sheath 840 (or both) or in sheath 820 or sheath 840 (or both), the nonwoven fabric has a thermoplastic material, a thermoset binder, an inorganic fiber, a metal fiber, a metallized inorganic fiber, and a metallized material. May contain synthetic fibers. While not shown, the decoration layer may be coupled to shell 820 or to shell 840 (or both). As mentioned herein, the decorative layer can be formed from a thermoplastic film, for example, polyvinyl chloride, polyolefin, thermoplastic polyester, thermoplastic elastomer, etc. The decorative layer can also be a multi-layered structure comprising a foam core formed from, for example, polypropylene, polyethylene, polyvinyl chloride, polyurethane, etc. The fabric may be bonded to a foam core, such as fabrics made from natural and synthetic fibers, needle punched, etc., followed by organic fiber nonwovens, raised fabrics, knitted fabrics, straight wool fabrics, or other such materials. The fabric can also be bonded to the foam core with thermoplastic adhesives, including pressure sensitive adhesives and hot melt adhesives such as polyamides, modified polyolefins, urethanes and polyolefins. Decorative layers can also be produced using spunbond, heat bonded, spunlace, melt-blown, wet, and/or dry processes.

In certain embodiments, two or more prepregs or cores can be coupled to each other and a skin can then be placed on each surface of the prepregs or cores. Referring to the following: Figure 9, an article 900 is shown comprising a prepreg or core 910 coupled to a prepreg or core 930 via an intermediate layer 920, and a shell 840 disposed on the core 940. If desired, sheath 940 may instead be disposed on prepreg or core 930 or another sheath (not shown) may be disposed on prepreg or core 920. Each prepreg or core 910, 930 may be the same or different. In some cases, the thermoplastic material and fibers of the prepreg or cores 910, 930 are the same, but the expandable graphite material load or type of expandable graphite material present in the prepreg or cores 910, 930 is different. In other cases, the type and/or amount of expandable graphite material in the prepreg or core 910, 930 may be the same and one or both of the thermoplastic materials and/or fibers may be different, for example, chemically different. may be present or may be present in different amounts. In some cases, covalently bonded expandable graphitic material may be present in one or more of the prepreg or core 910, 930. In other cases, non-covalently bound expandable graphitic material may be present in one or both prepregs or cores 910, 930. If desired, one or more suitable flame retardants, such as halogenated or non-halogenated flame retardants, may be present in one or both of the prepreg or cores 910, 930. While the thickness of the prepreg or cores 910, 930 is shown below to be approximately the same: Figure 9, the thickness of the prepreg or cores 910, 930 can vary. In some forms, one of the prepregs or cores 910, 930 may include a lofting agent other than an expandable graphite material, such as microspheres. The microspheres may be present in combination with an expandable graphite material or may be present in one of the cores 910, 930 without any expandable graphite material. Layer 920 and shell 940 may independently include, for example, a film (e.g., a thermoplastic or elastomeric film), a prim, a scrim (e.g., a fiber-based scrim), a foil, a fabric, a non-woven fabric, or It may be present as an inorganic coating, an organic coating, or a thermoset coating disposed on the prepreg or core 830. In other cases, layer 920 and shell 940 may independently include a limiting oxygen index greater than about 22, as measured according to ISO 4589, 1996. When the thermoplastic film is present as layer 920 or sheath 940 (or both) or in layer 920 or sheath 940 (or both), the thermoplastic film comprises at least one poly(ether imide), poly(ether ketone), poly(ether) -ether ketone), poly(phenylene sulfide), poly(arylene sulfone), poly(ether sulfone), poly(amide-imide), poly(1,4-phenylene), polycarbonate, nylon, and silicone. may include. When a fiber-based scrim is present as or in layer 920 or sheath 940 (or both), the fiber-based scrim is comprised of at least one glass fiber, aramid fiber, graphite fiber, carbon fiber, or inorganic mineral. Can include fibers, metal fibers, metallized synthetic fibers, and metallized inorganic fibers. If the thermoset coating is present as layer 920 or sheath 940 (or both) or in layer 920 or sheath 940 (or both), the coating comprises at least one unsaturated polyurethane, vinyl ester, phenolic and epoxy. can do. If the inorganic coating is present as layer 920 or shell 940 (or both) or in layer 920 or shell 940 (or both), the inorganic coating may contain cations selected from Ca, Mg, Ba, Si, Zn, Ti and Al. It may contain minerals or may contain at least one of gypsum, calcium deoxidation and mortar. When the nonwoven is present as layer 920 or sheath 940 (or both) or in layer 920 or sheath 940 (or both), the nonwoven may be a thermoplastic material, a thermoset binder, an inorganic fiber, a metal fiber, a metallized inorganic fiber, and a metallized material. May contain synthetic fibers. While not shown, the decoration layer may be coupled to the skin 920 or prepreg or core 930 (or both). As mentioned herein, the decorative layer can be formed from a thermoplastic film, for example, polyvinyl chloride, polyolefin, thermoplastic polyester, thermoplastic elastomer, etc. The decorative layer can also be a multi-layered structure comprising a foam core formed from, for example, polypropylene, polyethylene, polyvinyl chloride, polyurethane, etc. The fabric may be bonded to a foam core, such as fabrics made from natural and synthetic fibers, needle punched, etc., followed by organic fiber nonwovens, raised fabrics, knitted fabrics, straight wool fabrics, or other such materials. The fabric can also be bonded to the foam core with thermoplastic adhesives, including pressure sensitive adhesives and hot melt adhesives such as polyamides, modified polyolefins, urethanes and polyolefins. Decorative layers can also be produced using spunbond, heat bonded, spunlace, melt-blown, wet, and/or dry processes.

In certain embodiments, strips of material may be disposed on a prepreg or core layer. Referring to the following: Figure 10, an article 1000 is shown comprising prepreg or core 1010 and strips 1020, 1030 disposed on different regions of prepreg or core 1010. If desired, the strip may be present in any of the exemplary implementations shown below: Figures 1A and 2A-9. Strips 1020, 1030 may be the same or different. In some cases, strips 1020, 1030 may include an expandable graphite material as mentioned herein. For example, the strip can include an expandable graphitic material that is non-covalently bonded to another material in the strip or can include an expandable graphite material that is covalently bonded to another material in the strip. In some cases, strips 1020, 1030 may independently take the form of prepregs or cores as described herein. In other forms, the strips may take the form of a skin or layer as described herein. In certain cases, the strips may be placed, for example, on areas of the article 100 where it may be desirable to provide structural reinforcement or on areas where differential thickness is desired. In cases where the strips 1020, 1030 include a lofting agent such as microspheres or an expanded graphite material, additional thickness in the region containing the strips 1020, 1030 can be achieved if desired.

In some embodiments, prepregs and cores may include additional materials or additives to impart desired physical or chemical properties. For example, one or more dyes, texturing agents, colorants, viscosity index improvers, smoke suppressants, synergistic materials, lofting agents, particles, powders, biocides, foams or other materials may be mixed with the prepreg or core, or It can be added to prepreg or core. In some cases, the prepreg or core may include one or more smoke suppressant compositions in an amount from about 0.2 weight percent to about 10 weight percent. Exemplary smoke suppressant compositions include, but are not limited to, stannates, zinc borates, zinc molybdates, magnesium silicates, calcium zinc molybdates, calcium silicates, calcium hydroxide, and mixtures thereof. If desired, synergist materials may be present to improve the physical properties of the prepreg or core. For example, synergists may be present that improve the flame retardant properties of the expandable graphite material. If desired, synergist materials may be present to improve lofting ability. Exemplary synergist materials include, but are not limited to, potassium sodium trichlorobenzene sulfonate, diphenyl sulfone-3-sulfonate, and mixtures thereof.

In other instances, the prepreg or core described herein includes a thermoset material in a desired amount, e.g., less than about 50 weight percent, based on the total weight of the prepreg or core, to impart the desired properties of the core. can do. Thermoset materials may be mixed with thermoplastic materials or may be added as a coating on one or more surfaces of the prepreg or core.

In certain embodiments, the prepregs or cores described herein may be constructed (or used as) a glass mat thermoplastic composite (GMT) or a lightweight reinforced thermoplastic (LWRT). One such LWRT is manufactured by HANWHA AZDEL, Inc. and sold under the brand name SUPERLITE® Metro. SUPERLITE® mats loaded with expandable graphite materials can provide desirable added properties, such as flame retardancy and improved processing capabilities. The areal density of such a GMT or LWRT may range from about 400 grams per square meter (gsm) to about 4000 gsm of the GMT or LWRT, although the areal density may be less than 400 gsm or greater than 4000 gsm depending on specific application needs. You can. In some embodiments, the top density can be less than about 4000 gsm. In certain cases, the GMT or LWRT may include an expandable graphite material disposed in the cavity of the GMT or LWRT. For example, non-covalently bound expandable graphitic material may be present in the vacuoles of the GMT or LWRT. In other cases, covalently-bonded expandable graphitic material may be present in the vacuoles of the GMT or LWRT. In yet another form, all non-covalently bonded expandable graphitic materials and covalently bonded expandable graphitic materials may be present in GMT or LWRT. When a GMT or LWRT prepreg or core is used in combination with an expanded graphite material, the basis weight of the GMT or LWRT can be reduced, for example, to less than 800 gsm, 600 gsm or 400 gsm while still providing suitable performance characteristics. You can. If desired, additional lofting agents, such as microspheres, may be present at GMT or LWRT.

In the production of prepregs and cores described herein, it may be desirable to use wet processes. For example, a liquid or fluid comprising materials, such as thermoplastic materials, fibers, and expandable graphite materials, optionally dispersed with any one or more additives (e.g., other lofting agents or flame retardants) described herein, may be a gas, For example, it may be stirred or agitated in the presence of air or other gas. The dispersion may then be placed on a support, such as a wire screen or other support, to provide a substantially uniform distribution of the expandable graphite material in the laid down material. To increase expandable graphite material dispersion and/or uniformity, the stirred dispersion may include: one or more activators, such as anionic, cationic, or non-ionic such as, Sold under the name ACE liquid by Industrial Soaps Ltd., sold as TEXOFOR® FN 15 material by Glover Chemicals Ltd., and sold as Amine Fb 19 material by Float-Ore Ltd. These formulations are available in liquid dispersions. It can help disperse the air. The components may be added to a mixing tank, flotation cell or other suitable device in the presence of air to provide a dispersion. While aqueous dispersions are preferably used, one or more non-aqueous fluids may also be used to assist in dispersion, to modify the viscosity of the fluid, or otherwise to impart desired physical or chemical properties to the dispersion or prepreg, core or article. It can exist.

In certain cases, after the dispersion has been mixed for a sufficient period of time, the fluid along with the suspended material may be placed on a screen, moving wire, or other suitable support structure to provide a web of underlying material. Suction or reduced pressure can be provided to the web to remove any liquid from the underlying material to leave behind thermoplastic materials, expandable graphite materials, and any other materials present, such as fibers, additives, etc. . As mentioned herein, by selecting the expandable graphite material particle size to be substantially equal to or greater than the average particle size of the thermoplastic material, improved retention of the expandable graphite material (compared to the level of microsphere retention) can be achieved. You can. The resulting web may be dried, consolidated, pressed, lofted, laminated, sized or otherwise processed to further provide the desired prepreg, core or article. In some cases, additives or additional expandable graphite materials may be added to the web prior to drying, consolidation, pressing, lofting, lamination, sizing or other further processing to provide the desired prepreg, core or article. In other cases, the expandable graphite material may be added to the web after drying, consolidating, pressing, lofting, lamination, sizing or other further processing to provide the desired prepreg, core or article. While wet processes may be used, depending on the nature of the thermoplastic material, expanded graphite material and other materials present, the air laid process, dry blend process, carding and needle process, or other known processes used in the manufacture of nonwoven products. It may be desirable to use instead. In some cases, the additional intumescent graphite material is passed through the board directly under a plurality of coating jets configured to spray the intumescent graphite material at an angle of about 90 degrees onto the prepreg or core surface, allowing the prepreg or core to cure to some extent. It can then be sprayed onto the surface of the prepreg or core.

In some forms, the prepregs and cores described herein can be produced by a combination of thermoplastic materials, fibers, and expandable graphite materials in the presence of surfactants in aqueous solutions or foams. The combined components may be mixed or agitated for a sufficient time to disperse the various ingredients and provide a substantially homogeneous aqueous mixture of the ingredients. The dispersed mixture is then placed on any suitable support structure, for example a wire mesh or other mesh or support having the desired porosity. Water can be vacuumed through a wire mesh forming a web. The web is dried and heated above the softening temperature of the thermoplastic powder. The web is then cooled and pressed to a predetermined thickness to produce a composite sheet having a pore content of about 1 percent to about 95 percent. In an alternative embodiment, the water-based foam also includes a binder material.

In certain examples, prepregs or cores may be produced in the form of GMT. In certain cases, GMT is made of shredded glass fibers, thermoplastic materials, expanded graphite materials and glass fibers or thermoplastic fibers such as, for example, polypropylene (PP), polybutylene terephthalate (PBT), polyethylene terephthalate (PET). ), polycarbonate (PC), a blend of PC/PBT, or a blend of PC/PET and/or an optional thermoplastic polymer film or films and/or woven or nonwoven. In some embodiments, PP, PBT, PET, PC/PET blends or PC/PBT blends can be used as high melt flow index resins. To produce the glass mat, thermoplastic materials, reinforcing materials, expandable graphite materials and/or other additives can be added or metered into the contained disperse foam in an upper mixing tank equipped with an impeller. Without wishing to be bound by any particular theory, the presence of trapped pockets of air in the foam can aid in the dispersion of glass fibers, thermoplastic materials, and expandable graphite materials. In some examples, the dispersed mixture of glass and resin may be pumped through a distribution manifold to a head-box located above the wire section of the paper machine. The foam, which is not glass fiber, expanded graphite material or thermoplastic material, can then be removed as the dispersed mixture is applied to a vacuum-assisted moving wire screen that continuously produces a uniform, fibrous wet web. The wet web may be passed through a dryer at a suitable temperature to reduce the moisture content and to melt or soften the thermoplastic material. When the hot web exits the dryer, surface layers such as, for example, films can be laminated to the web by passing glass fibers, expanded graphite materials, thermoplastic materials and films through the nips of a set of heated rollers. If desired, additional layers such as, for example, non-woven and/or textile layers may also be attached along the film to one or both sides of the web to facilitate handling of the glass fiber-reinforced mat. The composite can then be passed through tension rolls and subsequently cut (cut) to the desired size for subsequent formation into final product articles. Additional information regarding the preparation of the GMT composites, including suitable materials and processing conditions used in forming the composites, is described, for example, in U.S. Pat. , 5,609,966, and U.S. Patent Application Publication Nos. US 2005/0082881, US2005/0228108, US 2005/0217932, US 2005/0215698, US 2005/0164023, and US 2005/0161865.

In certain embodiments, the presence of EG materials in combination with thermoplastic materials and reinforcing fibers allows for better contrast in loft than can be achieved with conventional liquid hydrocarbon-polymer shell microspheres. For example, by selecting EG materials that are substantially insensitive to convective heating and susceptible to: other types of heating, such as IR heating, prepregs, cores and articles can be produced with high pre-lofting capacity. You can. This form allows the end user to have a wide range of possible final thicknesses for parts including prepregs, cores and articles. For example, the end user can select the desired heating conditions to process a part that provides the desired resulting thickness. If desired, different sections of the part can have different final thicknesses by varying the processing conditions applied to specific sections.

In some cases, prepregs, cores or articles can be produced by combining thermoplastic materials, reinforcing fibers and expandable graphite particles in a mixture to form an agitated aqueous foam. The agitated aqueous foam can be placed on a wire support. Water can be vacuumed to form a web or open cell structure. The web may be heated using convective heating, for example, above the melting temperature of the thermoplastic material under conditions that result in substantially no loft, a step also referred to in some cases as integration. If desired, the pressure is applied to a thermoplastic composite sheet comprising expandable graphite particles, for example, uniformly dispersed in a web (or open cell structure) or non-uniformly dispersed in the web (or open cell structure). It can be applied to the web to do this. Sheets can be further processed by selection of suitable heating conditions to provide the desired loft. In some cases, heating conditions effective for lofting the sheet can be applied to increase overall board thickness. For example, a skin, cover layer or other material can be disposed on a sheet. The multi-layer assembly can be placed in a mold and heating conditions can be applied to loft the sheet to press its surface against the other layers of the assembly. By increasing the overall thickness of the sheet, better adhesion can be achieved between the sheet and other layers of the assembly.

In certain cases, methods for producing composites include combining thermoplastic materials, reinforcing fibers, and expandable graphite particles in a mixture to form an agitated aqueous foam. The foam is placed on a wire support and water is vacuumed to form a web or open cell structure containing thermoplastic, fiber and graphitic materials. In some cases, the web is then heated to a first temperature above the melting temperature of the thermoplastic material, where the first temperature is below the loft onset temperature of the expandable graphite particles and thereby substantially no loft occurs. In other cases, the web may be heated using heating conditions that melt the thermoplastic material, such as convection heating, but do not substantially loft the expandable graphite particles. If desired, pressure can then be applied to the web, for example, using a nip roller or other device, to provide a thermoplastic composite sheet comprising expandable graphite particles dispersed in the web.

Specific examples are set forth below to further illustrate some of the novel aspects and configurations described herein.

Example 1

Different compositions were produced using polypropylene resin and glass fiber. One composition (H1100) comprising liquid hydrocarbon core-polymer microspheres present at 5 weight percent. The second composition included EG-249C expanded graphite (EG) material present at 5 weight percent. The third composition included EG-249C expandable graphite material present at 10 weight percent. The fourth composition included EG-249C expandable graphite material present at 15 weight percent. The fifth composition included EG-HV expandable graphite material present at 10 weight percent. About 60 weight percent polypropylene and 40 weight percent glass fiber were present in each composition. The weight percent of EG in each composition was based on the total weight of polypropylene and glass fiber, for example, a composition with 5 weight percent EG would have 5 g of EG in a composition containing 40 g of glass fiber and 60 grams of polypropylene. It can be produced by addition of EG. Each composition was made into a sheet with a basis weight of approximately 800 gsm.

The boards were tested for thickness change under various heating conditions. The H1100 and EG-HV containing boards were air heated at: 204 degrees Celsius (left column below: Figure 11) and air heated at: 225 degrees Celsius (right column below: Figure 11). Each EG-249C board was air heated at the same temperature and also treated with infrared heating (IR) at 200 degrees Celsius and 220 degrees Celsius (bars from left to right below are: Figure 11 for EG-249C below) Represents air heating at: 204 degrees Celsius, air heating at: 225 degrees Celsius, IR heating at: 200 degrees Celsius, and IR heating at: 220 degrees Celsius; the bars in EG-HV represent air heating at: 204 degrees Celsius and 225 degrees Celsius).

Microspheroid board thickness increased at all temperatures with thickness at lower temperatures closely related to thickness at higher temperatures. Compared to microspheres, EG-249C boards were generally insensitive to air heating, showing no or little thickness change. EG-HV board thickness increased upon air heating. EG-HV is a lower grade expandable graphite material and expands at lower temperatures than EG-249C. The thickness of all EG-249C boards was increased dramatically using IR heating at: 220 degrees Celsius. Additionally, the thickness of the board was varied along with the amount of expandable graphite material loading and the IR heating temperature. The results are consistent with the use of an expandable graphite material to selectively increase board thickness by selection of the desired lofting temperature.

Example 2

A series of boards were manufactured using the process described in Example 1. The boards each contained similar amounts of polypropylene and glass fiber as mentioned in Example 1. Three different boards were manufactured: one with H1100 microspheres, one with N351 expandable graphite material, and one with N400 expandable graphite material. Each board was tested for one cycle by convection heating at: 200 Celsius temperature. The results are shown in Table 1. A 99 mm diameter round puck was used as a test specimen. Thickness was measured in three different sections using calipers.

The results were consistent with the thickness of each board increasing over time with continued heating. There is significant collapse in the microspheroid board (H1100) with increased heating as the thickness is reduced from 2 to 4 minutes. No collapse of the intumescent graphite material board was observed.

Example 3

To determine the preliminary lofting capacity (how much additional thickness could be achieved) of the three boards of Example 2, each board was cooled at room temperature for 1 day. The boards were then treated twice by convection heating at: 200 degrees Celsius for 3 minutes (for H1100 boards) and by IR heating at approximately 220 degrees Celsius for 1.5 minutes (for EG boards). The microspheres board (H1100) was subjected to different heating conditions allowing maximum loft without rupture of the microspheres. The results are listed in Table 2.

The loft induced in stage 1 represents a loss of potential lofting capacity. For example, for an H1100 board with an overall thickness of 8.892 mm, the induced loft in period 1 was 5.526 mm. The total thickness of the board was 8.892 after period 2 loft, meaning that the board was lofted to 5.526/8.892 = 62.1% of its total lofting capacity after period 1. The results mean that only 37.9% reserve lofting capacity remained in the board.

In contrast, the expanded graphite material board maintained 73.5% pre-lofting capacity for N351 and 64.4% pre-lofting capacity for N400 at similar times. These results are consistent with the expandable graphite material providing additional pre-lofting capacity when compared to microspheres.

Example 4

Additional tests were performed using the board of Example 2. These tests included measurement of the ash content as well as the basis weight of each board during heating and determination of the loft index after lofting the boards at the following temperatures: 200 degrees Celsius (using convection heating in an oven). 99 mm diameter pucks were used as test samples with 10 pucks used for each experiment. For full data, thickness values are based on the average measurement over all 10 pucks. Base weight, coefficient of variation (COV), thickness, loft ratio (lofted thickness divided by as-is thickness), ash (determined by placing the sample for combustion in an 800 degree C oven - only glass fibers remain. and remaining is the weight percent of glass fiber), Loft-Index-1 (loft ratio divided by ash), Lofting Agent Content (shown in Table 3 below: Figure 12 as MS content) and Loft-Index-2 (Lofting Agent The loft index-1) divided by content was determined. Use of the loft-index can remove (or normalize) the variation in the total gsm of each board, leading to directly comparable results. Microspheres content (H1100) was determined by gravimetry before and after microspheres rupture to calculate the content of microspheres in the sample. For EG (N351 and N400) the 7% content was based on the addition of that amount of EG to the test sample. The results are shown in Table 3 below: Figure 12

The lofting index of all EG samples (N351 and N400) was at least 50% less than that of the corresponding microspheres samples at the same heating time. These values are consistent with EG containing boards that provided improved pre-lofting capacity after convective heating at: 200 degrees Celsius.

Example 5

Additional tests were performed using the board of Example 2. These tests included measurement of the basis weight of each board as well as the batch during heating and determination of the loft index after lofting the boards at the following temperatures: 220 degrees Celsius (using convection heating in an oven). Results were obtained/determined as described in connection with Example 4. The results are shown in Table 4 below: Figure 13.

The lofting index of the full EG samples (N351 and N400) was less than that of the corresponding microspheres samples at the same heating time. The loft index at each heating time for each sample was generally greater than the corresponding loft index obtained at 200 degrees Celsius. These values are consistent with EG, which provided improved control of lofting by varying the processing temperature.

Example 6

Different types of expandable graphite materials were tested by producing boards similar to the boards of Example 2. The weight percentage of each expandable graphite material in the board was 8 weight percent. The H1100 microspheres control board contained 24 weight percent microspheres. The standard weight of each board was approximately 800 gsm. Loft was measured under various conditions listed in Table 5. TMA refers to the onset temperature determined by the use of a thermomechanical analyzer to measure the actual temperature onset of the starting loft. The NYACOL value is the corresponding value provided by the supplier.

The results in Table 5 are consistent with the expandable graphite material providing high pre-lofting capacity after convective heating at 200 degrees Celsius for 1 minute. For HV, 351 and KP251 EG materials, the ability to achieve high loft at: 220 degrees Celsius (for 1 minute) provides reserve loft capacity in boards containing these materials. A bar graph comparing loft thickness under various conditions is shown below: Figure 14. Each bar grouping from left to right shows: Air heating at 200 degrees Celsius, Below air heating at 220 degrees Celsius. IR heating at: 200 degrees Celsius and IR heating at: 220 degrees Celsius. As shown in the graph, EG samples are sensitive to the type of heat applied. This selectivity allows better control of lofting by selection of a suitable heat application process. In contrast, microspheres lofts are generally insensitive to the type of heat applied. In certain cases, it is desirable to select an EG material based on the retention of a large gap between: loft at: 200 degrees Celsius and loft at: 220 degrees Celsius. Larger gaps provide more reserve loft capacity. Additionally, by selecting a large gap and using EG materials that do not provide substantial loft under convective conditions, infrared heating (or other heating) can be applied to better control the final thickness of the article.

Example 7

The ability of expandable graphite materials (in the absence of flame retardants) to provide flame retardancy to thermoplastic composites was tested. A control board containing H1100 microspheres and a test board containing various extensible graphite materials were tested. The results are shown in Table 6 below: Figure 15. Parentheses indicate the expandable graphite material loading in percent by weight on each board. Each board contained a base weight of approximately 800 gsm and was molded to a thickness of approximately 2 mm. Burning speed was measured in inches/minute as shown in the 1991 FMVSS 302 test as described herein. Burning distance was measured in inches as indicated in the FMVSS-302 test method.

The results are consistent with the self-annihilation performance in unaffected expanded graphite material boards before and after lofting. At a 5% EG-249C load, the board was self-extinguishing, indicating that flame retardancy can be provided by as little as 5% by weight expanded graphite material. In comparison, the microspheroid board was not self-destructive. The timing marks in Table 6 refer to marks approximately 4 inches inward and from the distal end of the flame applied to the board.

Example 8

An additional set of boards was tested for flame retardancy. The materials used and their load weights are shown in Table 7 below: Figure 16. All intumescent graphite material boards were self-extinguishing when the boards were molded down to 2 mm. As the porosity of the board increases, it generally becomes more difficult to pass the self-extinguishing test. All the intumescent graphite material boards were self-extinguishing, even when they were loaded and molded to a total thickness of 8 mm, meaning that there was more air or higher porosity present.

Example 9

Several boards were tested for their non-oil and oil flammability. The board had a base weight of approximately 1310 gsm. The boards each contained a Superlite ^TM core (a mixture of polypropylene and approximately 55 weight percent glass fiber) in combination with approximately 10 weight percent Asbury 3335 expanded graphite material. There was no decrease in tensile strength in the longitudinal or transverse directions after the board aged. Aging involved exposure of the boards to heat and water at different times and humidity values, including 48 hours at: 38 +/- 2 degrees Celsius, and 95 +/- 2 percent relative humidity. A long-term thermal cycle of 7 days is given below: 150 degrees Celsius was also used to age the boards. The board was then soaked in distilled water for 48 hours at room temperature.

The boards were also tested for their ability to become self-destructive in the presence of oil or no oil. The 2013 SAE J369 test (equivalent to the FMVSS 302 test described herein) was used to test flammability. The test results are shown in Table 8 listed below: Figure 17. The entire board passed the oil flammability test (referenced as SE/0 in Table 8). At the following process temperatures: 200 degrees Celsius, there was 8.10 mm of free loft. At the process temperature: 220 degrees Celsius, there was 12.46 mm of free loft (preliminary loft capacity less than: 200 degrees Celsius board). At the process temperature: 240 degrees Celsius, there was 22.97 mm of free loft (preliminary loft capacity less than: 220 degrees Celsius board). Five replicates of each board were tested. As noted in more detail above, “B” in Table 8 refers to boards observed for burning. Cells listed "B" were boards where the flame traveled on the surface rather than inside the core. Movement inside the core is desirable as the expandable graphite inside the core can, at least partially, assist in extinguishing the flame.

Another board is about 10 weight percent Asbury 3335 expanded graphite material and 2 weight percent DJ Semichem. Microspheres were produced using the same core material with lofting agent (but with 45 weight percent glass). When molded to 8 mm thickness, the board exhibited SE/0 performance in the oil self-quenching test (passed the SAE J369 test). These results were consistent with the expanded graphite material, which provided boards that passed the flammability test while still having a ready lofting capacity to allow further processing, e.g., forming, into desired parts or shapes.

Example 10

Several additional boards were produced containing similar amounts of expanded graphite material but different loft thicknesses. The boards produced contained Superlite ^TM cores in combination with EG materials. The boards listed are shown in Table 9.

Boards lofted to 6-7 mm (Run 1) can be processed in a similar way to the Superlite ^TM core without any EG, for example, molded at similar temperatures as the Superlite ^TM core without any EG. For Runs 1 and 2, there was a 90 gsm HOF scrim on one side of the core and a 225 gsm polypropylene film on the other side of the core. For Run 3, there was a 20 gsm polyethylene terephthalate (PET) scrim on one side of the core and a 98 gsm polypropylene film on the other side of the board. Some wrinkling was observed for the lofted boards between 8-9 mm (Run 2). Boards lofted beyond the 9 mm free loft could be processed in a similar manner to the Superlite ^TM core and had reduced cycle times compared to the Superlite ^TM core alone.

Example 11

The board may be manufactured to a core weight of approximately 1200 gsm and may include glass fiber (40-60 weight percent), 5-15 weight percent expanded graphite material, optionally 0-5 weight percent microspherical lofting agent, and the remainder. is a thermoplastic material such as polyolefin, for example polypropylene. If desired, a shell material such as a scrim can be deposited, for example, on one or more sides of the core material. In some cases, the flame retardant scrim can be disposed on one surface and the non-flame retardant scrim can be disposed on the opposite surface. The exact basis weight of the scrim can vary from about 20 gsm to about 100 gsm. In other cases, one side of the core may include a film such as a polyolefin film.

Example 12

The expansion rates of three different expandable graphite materials as a function of increasing temperature were tested. The results are shown below: Figure 18. In comparing different EG materials, the 3335 material had a lower expansion ratio in the temperature range between: 160 degrees Celsius and 220 degrees Celsius. These results are consistent with the selection of the expandable graphite material to have an appropriate loft temperature for a particular processing temperature. For example, if lofting is desired: 170 degrees Celsius, Nyagraph KP251 can be used. When lofting is required: 180 degrees Celsius, Nyagraph KP251 or Asbury 3721 (or both) may be used.

When introducing elements of the embodiments disclosed herein, the articles and “said” are intended to mean one or more elements. The terms “comprising,” “comprising,” and “having” are intended to be open-ended and mean that there may be additional elements other than the listed elements. Given the benefit of the present disclosure, it will be appreciated by those skilled in the art that various elements of an embodiment may be exchanged or substituted for various elements in other embodiments.

Although certain aspects, embodiments, and implementations have been described above, additions, substitutions, modifications, and variations of the disclosed exemplary aspects, embodiments, and implementations will be appreciated by those skilled in the art, given the benefit of the present disclosure. It will be recognized technically.

Claims (100)

A thermoplastic composite comprising a porous core layer comprising a web of an open-celled structure comprising random intersections of a plurality of reinforcing fibers held together by a polyolefin thermoplastic material, comprising:
The porous core layer has a porosity of 20%-95%,
The porous core layer further includes an expandable graphite material uniformly dispersed in the vacancies of the open cell structure of the porous core layer,
The expandable graphite material is uniformly distributed in a web of an open-celled structure from the first surface of the porous core layer to the second surface of the porous core layer,
The thermoplastic composite meets the 1991 Federal Motor Vehicle Safety Standard 302 (FMVSS 302) flammability test, is self-extinguishing, and
the expandable graphite material is lofted at a loft temperature at least 20 degrees Celsius above the melting point of the polyolefin thermoplastic material,
A thermoplastic composite product, wherein the porous core layer further includes expanded graphite particles covalently bonded within a web of the open-celled structure of the porous core layer, and wherein the porous core layer does not include an added flame retardant. 2. The thermoplastic composite of claim 1, wherein the expandable graphite material is effective to increase the thickness of the porous core layer by at least 50% after radiation heating. 2. The thermoplastic composite of claim 1, wherein the expandable graphite material is selected to be insensitive to loft upon convective heating. The method of claim 1, wherein the plurality of reinforcing fibers comprises at least one of glass fibers, aramid fibers, graphite fibers, carbon fibers, inorganic mineral fibers, metal fibers, metallized synthetic fibers, and metallized inorganic fibers. Thermoplastic composite. The thermoplastic composite article of claim 1, wherein the polyolefin thermoplastic material includes at least one of polyethylene, polypropylene, and mixtures thereof. The method of claim 1, wherein the polyolefin thermoplastic material comprises particles, and the expandable graphite material comprises expandable graphite particles,
A thermoplastic composite product, wherein the difference between the average particle size of the particles of the polyolefin thermoplastic material and the average particle size of the expandable graphite particles is less than 50% similar. 2. The thermoplastic composite of claim 1, wherein the porous core layer provides flame retardancy and is halogen-free. The thermoplastic composite product of claim 1, further comprising a lofting agent in the porous core layer. The thermoplastic composite product of claim 1, further comprising a skin disposed on the porous core layer. 10. The thermoplastic composite of claim 9, wherein the expandable graphite material is effective to increase the thickness of the porous core layer by at least 50% after radiation heating. 10. The thermoplastic composite of claim 9, wherein the expandable graphite material is selected to be insensitive to loft upon convective heating. The method of claim 9, wherein the plurality of reinforcing fibers comprises at least one of glass fibers, aramid fibers, graphite fibers, carbon fibers, inorganic mineral fibers, metal fibers, metallized synthetic fibers, and metallized inorganic fibers. Thermoplastic composite. 10. The thermoplastic composite article of claim 9, wherein the polyolefin thermoplastic material includes at least one of polyethylene, polypropylene, and mixtures thereof. 10. The method of claim 9, wherein the polyolefin thermoplastic material comprises particles, the expandable graphite material comprises expandable graphite particles, and the average particle size of the expandable graphite particles is at least 50% of the average particle size of the polyolefin thermoplastic material particles. , thermoplastic composite. 10. The thermoplastic composite of claim 9, wherein the porous core layer provides flame retardancy and is halogen-free. 10. The thermoplastic composite article of claim 9, further comprising a lofting agent in the porous core layer. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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